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[Display omitted] • Designing materials using rice-leaf-mimetic paper as a substrate. • Engineering rice-leaf-mimetic paper with hydrochromic dyes or biolubricants. • Processes based on mass-producible papermaking unit operations. Biomimetics has revolutionized materials innovation by drawing inspiration from biological systems. Cellulosic paper, a sustainable biomaterial, offers immense potential for biomimetic research. Paper-based biomimetic materials, which replicate the structures and functionalities of natural materials by utilizing the cellulosic fiber network as a substrate or skeleton, provide customizable functional properties, thereby enabling advanced applications. Here, we introduce rice-leaf-mimetic paper, inspired by the leaf's microstructure and biowax-based cuticle. This paper exhibits self-cleaning superhydrophobicity and showcases possibilities for additional functionalities, including antibacterial properties and food preservation, as evidenced in our prior research. We propose its utilization as a substrate for rewritable and biolubricant-infused surfaces. These somehow distinct surfaces draw inspiration from the chemistry and microstructure of the rice leaf. Although incorporating hydrochromic dyes enables rewritability, controlling the retention time of colors remains challenging. The biowaxy structure of the paper prolongs color maintenance by inhibiting water evaporation. Moreover, the hierarchically rough microstructure of rice-leaf-mimetic paper effectively stores biolubricant molecules, reducing friction and enhancing slipperiness. Surface microcavity ratio analysis provides insights into the paper's biolubricant-storability. The surface engineering of rice-leaf-mimetic paper using hydrochromic dyes or biolubricants holds potential for designing novel materials. Unveiling the vast potential of easily scalable papermaking processes alongside biomimetics and surface engineering opens new avenues for materials innovation. [ABSTRACT FROM AUTHOR]

• Sea urchin-like MnO 2 reinforced carbon fiber paper interface. • Optimized structure of surface insulation and internal conduction. • Thickness optimization impedance matching, adjust the medium factor. • The material has frost resistance and certain stability. With the advent of the information age, the proliferation of intelligent devices has also given rise to the issue of electromagnetic pollution. Flexible materials hold significant applications and development prospects in the realm of electronic device shielding. In this study, MnO 2 was synthesized through reduction on the surface of carbon fiber paper (CFP), while conductive carbon black (CB) was incorporated into silicone rubber to fabricate a flexible polymer with both surface relative insulation and internal electromagnetic shielding capabilities. Under 1 wt% CB loading, the modified CFP exhibited an electromagnetic shielding performance reaching 33.22 dB, which is 49.5 % higher than that of its original counterpart. By optimizing the thickness of CB within the silicone rubber matrix filling component, impedance matching properties were enhanced for improved material performance. Adjusting medium factors by thickness optimization, at a thickness of 5 mm, the absorption coefficient A for electromagnetic waves entering into the modified CFP increased by 461.7 % compared to that observed in its original form. Furthermore, a contact angle as high as 110° was achieved on the surface of CFP indicating excellent hydrophobicity; moreover, stable adhesion between conductive fillers and surfaces was confirmed through testing procedures conducted thereafter. Additionally, even after undergoing more than ten freezing experiments, over 99 % electromagnetic shielding performance was retained by our developed material ensuring its viability under harsh low temperature conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of hierarchical porous hollow carbon fiber paper with oxygen vacancies. • Construct a multi-layered pores electrode, with a specific surface area of 205.58 m2 g−1. • The OV-TiO 2-X @HPHCFP electrode shows a high areal capacitance of 1608.2 mF cm−2 at 2 mA cm−2. • The dual OV double electrolytes supercapacitor delivers a high potential of 2.5 V and an energy density of 0.196 Wh cm−2. The inherent limited energy density in supercapacitors constitutes a substantial impediment to their widespread adoption and large-scale production. In this study, we have devised a novel cathodic electrode denoted as OV-TiO 2-X @HPHCFP, featured with rich oxygen vacancies and its hierarchical porous hollow structure. The OV-TiO 2-X @HPHCFP cathode manifests an impressive areal capacitance of 1608.2 mF cm−2 at the current density of 2 mA cm−2, coupled with a remarkable capacitance retention of 97.7 % after 10,000 charge–discharge cycles. Theoretical calculations corroborate that the presence of oxygen vacancies enhances the conductivity of the electrode, facilitating expedited charge transfer kinetics. Furthermore, the electrode integrated into a double electrolyte flexible supercapacitor configuration, denoted as OV-TiO 2-X @HPHCFP//PVA-Na 2 SO 4 /PVA-LiCl//OV-MoO 3-Y @CFP, operated at an effective potential of 2.5 V, can yield an energy density of 1.96 × 10−1 mWh cm−2 at a power density of 1.25 mW cm−2. This investigation thereby delineates a promising strategy for the development of supercapacitors that can attain elevated operational potentials with concomitant enhancements in energy density. [ABSTRACT FROM AUTHOR]

• Super-flexible, wearable, ultralight self-driven SBPD achieved through fabricating an a-Ga 2 O 3 film on different paper substrates (glossy, parchment, 75 GSM) with interdigitated Pt electrodes via magnetron sputtering. • The self-driven device exhibits an ultra-high responsivity of 20.96 mAW−1 and fast response speeds (65/67 ms) on a 75 GSM paper for 266 nm wavelength. • The device on 75 GSM paper demonstrates a UV-C/Vis rejection ratio exceeding ∼ 106, a high specific detectivity (∼1011 Jones), ultra-high responsivity (1.38 × 103 mAW−1), and an ultra-low NEP of 2.44 × 10-13 WHz−1/2 @ 5 V bias. • Exhibited exceptional flexibility, withstanding bending endurance (lo/l = 5) and maintaining stable performance throughout 600 bending cycles over two months. To address the growing demand for wearable optoelectronic devices in secure communication, environmental monitoring, biomedical, and military applications, the development of self-driven solar-blind photodetectors (SBPDs) is crucial. This work reports the fabrication of super-flexible, wearable, and ultralight self-driven SBPD based on an amorphous-Ga 2 O 3 film grown on various paper substrates (including glossy, parchment, and 75 GSM paper) with interdigitated Pt electrodes using a magnetron sputtering. The developed device on glossy, parchment, and 75 GSM paper exhibits superior responsivity of 8.30 mAW−1, 14.53 mAW−1, and 20.96 mAW−1, along with a fast response speed of 115/118 ms, 90/95 ms, and 65/67 ms for 266 nm light irradiation under self-driven conditions. Comparatively superior performance is recorded for 75 GSM paper-based device, owing to their surface roughness, porosity, and microfibrous structure, which enhance light absorption in the device. In addition, the developed device shows an ultraviolet C-to-visible rejection ratio of over ∼ 106, a high specific detectivity of 2.01 × 1011 Jones, a high responsivity of 1.38 × 103 mAW−1 and a low noise equivalent power of 2.44 × 10-13 WHz−1/2 at a 5 V bias on 75 GSM paper. The photocurrent remains close to its initial values even when bent to l o /l = 5, demonstrating outstanding flexibility, bending endurance, and deformability. The performance of the self-driven PD remains stable over two months and steady up to 600 bending cycles. Further, the fabricated device underwent thorough testing across various wearable applications, and the analysis demonstrates discernible alteration in its performance across real-world scenarios. This technique paves the way for developing self-driven paper-based SBPDs with high-performance, wearable, next-generation flexible optoelectronic device applications. [ABSTRACT FROM AUTHOR]

• Hydroxyapatite (HAP) composite paper with biocompatibility and hygroscopicity was prepared. • HAP composite paper has better hygroscopic and triboelectric properties than pure paper, making it more suitable for wearable sensing applications. • The HAP composite paper-based triboelectric nanogenerator can detect and distinguish different joint movements. • Hemostatic and disposable HAP composite paper can be degraded in the natural environment without harm. Wearable triboelectric nanogenerators (TENGs) have attracted considerable attention in the field of self-powered sensors that can be worn on the skin directly without packaging because of their breathability, conformability, and sensitivity to collect biomechanical energy. However, high humidity on the skin can affect the wearable TENG output performance, substantially affecting the sensor performance and stability. When worn for a long time, humidity can even cause skin inflammation. Thus, for a wearable TENG, moisture control and biocompatibility are also key factors that need to be addressed. Herein, we report a hygroscopic and biocompatible paper-based TENG using a hydroxyapatite (HAP) mineral coating to enhance the paper fiber. The mineral coating can maintain the surface of the paper fiber, which will not cause large external deformation of the paper fiber under a force, avoid squeezing out excess water, and keep the friction surface dry, avoiding humidity affecting the output performance. Without interfering with the performance of the TENG, the maximum water absorption of the HAP composite paper is ∼8 μL. The HAP composite paper–based TENG (4 cm2) has an open-circuit voltage and short-circuit current 5.8 times and 4.2 times that of pure paper, respectively, and can obtain 80.4 mW/m2 output and directly light 117 LEDs. At relative humidity values of 25.7 %, 43.1 %, and 58.8 %, the performance retained the peak values of 80.2 %, 68 %, and 63.7 %, respectively. Even at a high relative humidity of 71.7 %, the triboelectric performance of HAP composite paper is retained 59.3 %, and the stability under humidity is better than that of pure paper (45.6 %). In addition, the mineral paper can even work with tissue fluid and output performance decreases by 43.8 %. The mineral-enhanced paper TENG with high power generation performance, hygroscopicity, biocompatibility, and degradability provides a new perspective for disposable wearable sensors, even in medical treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple synthesis method has been developed for Ag@ZIF-8, involving controlling the loading and size of Ag NPs. • Ag@ZIF-8 meet the requirements for antibacterial agent used in the melamine-impregnated paper. • The multiple synergistic antibacterial mechanism of Ag@ZIF-8 was verified. • The decorated blockboards with 0.20 wt% Ag@ZIF-8 reached Level Ⅰ antibacterial grade. Melamine-impregnated paper, a decorative material in furniture and interior design, could potentially impede the spread of indoor bacteria if it possesses antibacterial properties. Here, nano Ag-doped ZIF-8 (Ag@ZIF-8) was synthesized using ion exchange and in-situ chemical reduction strategies, followed by incorporating it into melamine-impregnated paper. The ion exchange mechanism of Zn2+ and Ag+ during ion exchange reactions was investigated. The structure of Ag@ZIF-8 was well-defined, with Ag nanoparticles evenly distributed on the surface of ZIF-8. Ag@ZIF-8 showed good thermal stability at 400 °C, meeting the requirements for the hot-pressing process of the melamine-impregnated paper. Ag@ZIF-8 exhibited enhanced ROS generation under visible light compare to ZIF-8, which was attributed to its reinforced light absorption and charge carrier separation facilitated by the localized surface plasmon resonance (LSPR) effect. The antibacterial activity of Ag@ZIF-8 was better than ZIF-8, owing to the multiple-synergistic antibacterial mechanisms of the ion release and ROS generation. Specifically, the 10-Ag@ZIF-8 exhibited MIC of 128 μg/mL and 64 μg/mL against E. coli and S. aureus , respectively. The signal intensity of •O 2 − induced by 10-Ag@ZIF-8 was 4.38 times higher than that of ZIF-8. As the addition of Ag@ZIF-8 increased, the antibacterial performance of melamine-impregnated paper improved. Considering the antibacterial property and economy of melamine-impregnated paper, 0.20 wt% was the optimal amount for 10-Ag@ZIF-8 decorated blockboard. This study proposes a novel approach for synthesizing MOF-based melamine-impregnated paper with antibacterial properties, aiming to reduce bacterial spread, minimize disease risks, and contribute to lowering overall healthcare costs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Paper mill sludge ash (pm SA) was used as catalysts to activate PMS. • Aerobic calcination was conducive to the exposure/formation of octahedral FeIII. • The O O bond fracture was the root pathway for FeIV O production. • The release of solid calcium in pm SA could inhibit the active decay of FeIV O. • The pm SA could effectively degrade similar pollutants in near-neutral water. The excellent performance of high-valent iron-oxo species (FeIV O) in the degradation of pollutants by activating peroxymonosulfate (PMS) had attracted much attention. However, the generation and reaction mechanisms were still unclear. In this study, iron-rich paper mill sludge was used as a raw material for the first time to prepare iron-based catalysts with abundant octahedral FeIII sites (Fe oct III). The results showed that the highest content of Fe oct III was found in the paper mill sludge ash obtained by aerobic calcination at 800 °C (pm SA800), and the pm SA800 could exhibit excellent catalytic activity (0.4785 min−1) and stability during the oxytetracycline (OTC) degradation process. The characterization and density functional theory (DFT) calculations further indicated that the Fe oct III was the dominant active site for FeIV O production. PMS tended to be adsorbed on two adjacent Fe oct III sites to form a [Fe oct III-OSO 2 OO(H)-Fe oct III] complex with a two-site adsorption configuration. Subsequently, the O O and O H bonds in [Fe oct III-OSO 2 OO(H)-Fe oct III] broken by absorbing energy, generating FeIV O. It's worth noting that the Ca species of pm SA800 effectively stabilized the pH of the reaction solution, which ensured the stable and continuous production of FeIV O. This work provides a new idea and insight for preparing catalysts that could produce FeIV O active species. [ABSTRACT FROM AUTHOR]

• A photothermal paper prepared by chemically dyeing filter paper, with an ultralow cost at 0.163 $ m−2. • Photothermal paper exhibits 1.53 kg m−2h−1 of evaporation rate, surpassing the thermodynamic limit of 2D evaporator. • A paper-assembled hopper-type 3D solar evaporator maintains 2.38 kg m−2h−1 in real seawater for 7-day operation. • WHO-compliant drinking water produced from multiple real saline waters. • 2.65 and 7.58 kg m−2 of freshwater collected from outdoor test of seawater in midwinter and late spring, respectively. Interfacial solar evaporation has been regarded as the promising technical option to produce fresh water from seawater and other real brines or contaminated water bodies. However, it still suffers in the high cost, complicated preparation, low-efficiency, and salt accumulation induced poor evaporation stability of solar evaporator. Herein, we propose a simple method to fabricate ultralow cost photothermal paper with high solar evaporation efficacy (1.53 kg m−2h−1 for water) by chemically dyeing a filter paper, which is based on the grafting polymerization of pyrrole-2-aldehyde (P2C) onto the cellulose in paper via hydroxyl-aldehyde acetalization and pyrrole-aldehyde condensation. The manufacturing cost of this photothermal paper was evaluated as low as 0.163 $ m−2. Furtherly, a hopper-type solar evaporator with efficient water supply was assembled by tailoring the above photothermal paper, which maintained evaporation rate at 2.38 kg m−2h−1 without any measurable decay from 7 d seawater evaporation test, reflecting the excellent stability for seawater desalination. It also can produce purified water (>2.10 kg m−2h−1) complying with the sewage discharge standards, even the WHO standard for drinking water from uranium-contaminated nuclear effluent, concentrated seawater of desalination plant, and real dyeing wastewater of textile dyeing plant, maintaining a high evaporation efficacy. Moreover, outdoor experiments in midwinter and late spring yielded a daily freshwater collection at 2.65 kg m−2 and 7.58 kg m−2, respectively, demonstrating its good applicability in all season. This work provides a cost-effective strategy to constructing high-performance solar evaporator for freshwater production from various real waters. [ABSTRACT FROM AUTHOR]

Nanopore protein (α-hemolysin) was used to detect sub-nanosized plastic particles leached from a PE-coated paper cup. These sub-nanosized plastic particles can increase the inflammation response of macrophages. [Display omitted] • Nanopore sensing detects sub-nanosized plastics in PE-coated paper cups. • Sub-nanosized plastic particles in paper cups were 1.8 times more detected in boiled water than in room temperature water. • Sub-nanosized and microplastic particles alter cell membrane dynamics. • Sub-nanosized plastic particles can induce inflammatory cell responses. In recent years, there has been growing global concern about environmental pollution, and the increasing use of plastic products has made microplastics a serious environmental pollutant worldwide. Accordingly, the development of microplastic detection methods and research on the harmful effects of microplastics on human health are being actively pursued. In this study, we detected particle leaching from PE-coated paper cups using label-free nanopore sensing to identify and quantify the presence of sub-nanosized plastic particles. Plastic particles leached from the paper cups were classified as < 1 nm and > 1 nm, and their interactions with artificial cell membranes and inflammatory responses in the cells were evaluated. The results demonstrated that in a commonly used paper cup, particles < 1.4 nm were present at a concentration of approximately 1.13 mM in hot water and 0.62 mM in room-temperature water. It was demonstrated that plastic particles < 1 nm could condense the artificial cell membrane, whereas particles > 1 nm could thicken the artificial cell membrane. Furthermore, both size ranges of particles leached from the paper cups triggered an inflammatory response in the cells, with the inflammatory response increasing in proportion to the concentration and treatment time. The detection and analysis revealed the presence of sub-nanosized plastic particles in PE-coated paper cups, which are commonly used in daily life. These particles pose health threats and contribute to environmental pollution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Catalyzed Diesel Particulate Filter is electrified for rapid regeneration. • Appling electricity pulse combusts almost all of soot in less than half a minute. • Soot reaction rate and energy efficiency surpass those of other methods. • Massive lattice oxygen of catalyst is stimulated for rapid soot combustion. • Surface sulfate decomposition is boosted to alleviate SO 2 poisoning. To address short-term emission of massive particulate matter (PM) from diesel engines, rapid regeneration of catalyzed diesel particulate filters (CDPF) based on soot combustion is a considerable challenge. Herein, we employed an aluminosilicate fiber-weaved ceramic paper (CP) as a filter matrix, on which highly active potassium-supported antimony-doped tin oxides (K/ATO) were coated to fabricate a CDPF. The K/ATO/CP monolith preserves the 3D-network structure of CP while incorporating the mesopores of K/ATO, providing potential for trapping soot particles effectively. Furthermore, electricity pulses are designed to pass through the conductive K/ATO coating on the monolith for CDPF regeneration, achieving nearly complete soot conversion within less than half a minute using 1400 J of energy input. Both the reaction rate and the energy efficiency surpass previously reported those of other methods for soot combustion. Mechanism studies revealed that the electricity pulse can stimulate the release of tremendous lattice oxygen from the catalyst and in turn trigger rapid soot combustion, and boost surface sulfate decomposition to alleviate SO 2 poisoning. This work presents an electrification strategy to realize rapid regeneration of CDPF for effective PM elimination utilizing onboard electricity system for hybrid powers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Catalytic properties of MoS 2 in presence of glucose has been studied using DFT. • Molecular level substrate-analyte interaction has been studied through NCI plot. • Mos 2 functionalized paper based electrochemical sensor for glucose has been developed. • The paper based electrochemical sensor shows good accuracy and selectivity. • The ML-driven smart app, GluQuantify, shows enhanced accuracy and resolution. A paper-based electrochemical sensor utilizing MoS 2 as sensing material is developed to quantitatively estimate glucose in a complex extracellular fluid matrix. The contribution of MoS 2 as sensing material is substantiated in the context of density functional theory formalism. The molecular modelling of MoS 2 and glucose interaction is elucidated through the theoretical estimation of non-covalent interactions and charge density difference plots. The charge transfer phenomenon during the oxidation of glucose molecule in electrochemical experiments is verified through electronic band structure analysis and frontier orbital theory. The electrochemical responses indicate that the sensor exhibits an average accuracy of nearly 96%, with a quantification limit of 100 nM. Furthermore, the chronoamperometric measurements highlight the superior sensitivity of the device in presence of various perturbing molecules. The obtained DPV responses were integrated with a robust machine learning-driven standalone app GluQuantify. This app precisely predicts the glucose concentrations in serum samples. The utilization of GluQuantify substantially elevates the overall accuracy of the sensing platform to 99% and automates the detection process. The application also enhances the resolution of the sensor to 0.01 µM, which mitigates the sensor resolution-related issues in manual estimation. [ABSTRACT FROM AUTHOR]

• Novel paper-based MOF/MIPs chip strategy was successfully proposed by the boron-functionalized MOF as scaffold. • A new fluorescence strip detection of SAL can be accomplished within 30 min with the LOD as low as 0.095 μg kg-1. • The interaction between RhB and SAL was clarified and approved to be effective and applicable for fluorescence detection. Mimetic recognition materials for rapid and selective analysis of foodborne contamination from complex foodstuff becomes a hot research topic in the field of food safety. In this work, borate-affinity-functionalized MOF/molecularly imprinted polymer paper-based microfluidic chips (FSU-BA@MIP) were prepared by growing functionalized MOFs on paper surface with 3-carboxyphenylboronic acid (3-CPBA) as the ligands, followed by coating of a MIP layer of salbutamol (SAL) through a borate-affinity surface imprinting strategy. Using the obtained paper-based chip as a mimetic recognition and specific enrichment module, the fluorescence sensing platform achieved visual rapid quantitative analysis of SAL with a linear range of 0.1 × 10−2–5.0 mg L−1. The limits of detection and quantification were calculated to be 0.095 and 0.290 μg kg−1, respectively, and the sample loading via lateral flow aid could be completed within 30 min. The obtained MOFs/MIPs paper chips provide an effective way for the rapid analysis of harmful contaminants from different animal-derived foods. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-BPQD was synthesized through a solvothermal method using formamide as N source and solvent. • The N-BPQD exhibit a bright blue fluorescence with high quantum yield of 73.7%. • N-BPQD on fPAD was used as a visual fluorescent sensing platform for detection of bilirubin. • The fluorescent sensor shows high sensitivity and selectivity to bilirubin. • N-BPQD was a good fluorescent probe for cellular imaging. A facile top down producing approach for synthesis and doping of a nitrogen doped black phosphorus quantum dots (N-BPQD) in one-pot was developed by solvothermal method with formamide as a nitrogen source and solvent. The nitrogen atoms had introduced into BPQD structure and exhibit a bright blue photoluminescent with a high quantum yield of 73.7 %. The morphology and chemical structure of N-BPQD was characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. A fluorescent paper analysis device (fPAD) was applied in rapid and cost-effective detection of biomarker bilirubin with naked eyes. The fPAD sensor present a high selectivity, stability and sensitive response to bilirubin in a wide linear range of 10 to 150 µM with a limit of detection limit as 26 nM (S/N = 3) and limit of quantitation as 86 nM (S/N = 10). The principles-based density functional theory, calculations on doping and binding energy of N-BPQD were analyzed via the density functional theory (DFT) simulations. Moreover, N-BPQD showed extremely low cytotoxicity, which is a promising as a good fluorescent probe for stem cell imaging application. This work provide a new platform for diagnosis of jaundice disease. [ABSTRACT FROM AUTHOR]

• PNFs are tightly wound around GO nanosheets through strong electrostatic interaction, forming a nacre like microstructure. • Chemical crosslinking and hydrogen bonding synergize with interlayer entanglement effect among different PNFs. • Nacre-inspired PBO papers exhibits excellent tensile strength and toughness as high as 338.3 MPa and 16.04 MJ/m3. • The paper exhibits excellent fatigue resistance, extreme temperature resistance (−196～300 °C), and chemical stability. In extreme environments, it is difficult to balance the strength and toughness of ultra-thin film materials. To address this problem, we propose a promising strategy to build ultra strong, tough and extreme environments resistant Poly(p-phenylene-2,6-benzobisoxazole) (PBO) papers with a nacre-like structure constructed by synergistic electrostatic interaction and interlayer entanglement through the sol–gel-film method and hot press orientation. Highly interconnected PBO nanofibres （PNFs） with positive charges are tightly wound around the anisotropic graphene oxide (GO) nanosheets with negative charges through strong electrostatic interaction, forming a nacre like microstructure. The addition of Fe (Ⅲ) can form a coordination bond with the amino group on PNFs. Chemical crosslinking and hydrogen bonding synergize with interlayer entanglement effect among different PNFs，which can effectively dissipate interlayer energy and alleviate the conflict between strength and toughness. The resultant tensile strength and toughness are as high as 338.3 MPa and 16.04 MJ/m3，which are 197.7 % and 425.4 % of those of the intrinsic PBO paper, respectively. Additionally, after 5000 folding-unfolding cycles, the tensile strength retention and toughness retention of the PBO/GO/Fe (PGFe) paper were still 85.4 % and 71.9 %, respectively. Moreover, the paper exhibits excellent tolerance to extreme temperature environments and showed extremely strong chemical stability. [ABSTRACT FROM AUTHOR]

This research successfully synthesized a cross-linking modified MXene composite material, which could be used in preparation of the paper-based humidity sensor to endow it with structural stability, antioxidant property, and efficient real-time humidity monitoring performance. [Display omitted] • The PMX6-A7 was prepared by the PEI/AgNO 3 cross-linking modifying MXene. • The flexible humidity sensor presented excellent moisture sensitivity and stability. • The assembled monitor possessed effective real-time humidity monitoring performance. • The ECP technology endowed this research potential for large-scale application. With an abundance of hydrophilic active sites present on the surfaces, MXene exhibits significant potential for application in the field of humidity monitoring. Nevertheless, achieving the high response intensity, excellent response sensitivity, structural stability, and oxidation resistance in the MXene-based humidity sensors remains a formidable challenge. Herein, we propose a humidity sensor made from the paper-based flexible sensor with copper electrode and polyethyleneimine/silver nitrate cross-linking modified MXene composite materials. The humidity sensor prepared in this work presents a satisfactory capacitance response rate (819.9 % in 97 % RH) and favorable sensitivity (6.9/11.9 s for response/recovery time). Meanwhile, the humidity sensor possesses outstanding structural stability (less than 3 % attenuation of the capacitance response after 100 bending cycles) and superior oxidation resistance. Moreover, the real-time humidity monitor assembled based on the humidity sensor has realized the effective monitoring of human skin humidity and dynamic respiration. Consequently, this study provides a viable approach for achieving reliable real-time humidity monitoring, demonstrating significant potential in the realms of intelligent actuators, sensing devices, and health care. [ABSTRACT FROM AUTHOR]

This work constructed chiral nanozymes (Cys@Au/Fe Hops) with high enantioselectivity activity by cysteine-induced synthesis. The nanozymes, proficient in detecting DOPA enantiomers, have been transformed into a test paper sensor, offering enantioselective catalysis and enabling visual chiral detection via a smartphone platform. [Display omitted] • The Chiral Cys@Au/Fe Hops was synthesized using a one-pot method with cysteine as a chiral inducer. • Remarkable enantioselective catalytic activity for DOPA enantiomers by L/D -Cys@Au/Fe Hops. • Steric effects on DOPA enantiomers catalyzed by L/D -Cys@Au/Fe Hops revealed through molecular dynamics simulations. • Development of chiral nanozymes into stable test paper sensor for visual DOPA detection. The development of enantioselective nanozymes holds profound significance in synthesizing chiral compounds and elevating analytical precision. Herein, we have synthesized chiral gold/iron hierarchically organized particles (Cys@Au/Fe Hops) possessing peroxidase-like catalytic activity, through a one-pot method using cysteine as a chiral inducer. The nanozymes exhibited remarkable enantioselective catalytic activity to 3,4-dihydroxy-phenylalanine (DOPA) enantiomer. Notably, L -Cys@Au/Fe Hops, comprising right-handed helical nanopetals, exhibited elevated catalytic efficiency for L -DOPA over D -DOPA, whereas the reverse held for D -Cys@Au/Fe Hops. The molecular dynamics simulations demonstrated hydrogen bonding interactions between the active site and substrate, thereby revealing how steric effects affected the enantioselective catalysis of chiral DOPA by L/D -Cys@Au/Fe Hops. Moreover, the chiral nanozymes were developed into a test paper sensor due to their exceptional stability, which can achieve the visual detection of DOPA enantiomer combined with a smartphone platform. This work is significant in advancing the design and practical utility of highly selective enzyme mimics. [ABSTRACT FROM AUTHOR]

Description: A multi-layer wrinkled structure of MWCNTs/polyimide aerogel-based paper was prepared using a simple method. This paper exhibits excellent responsiveness, thermal stability, and mechanical properties, and can detect the movement of mechanical devices through generated responsiveness. [Display omitted] • Multilayer wrinkled structure MWCNTs/polyimide aerogel-based paper (CPs) was prepared via a single freeze-drying-thermal extrusion-thermal imidization method. • CPs can stably generate electrical responses in high-temperature environments up to 300 °C. • CPs exhibit good tensile strength (CP-1: 117.1 MPa at 25 °C) and stability (1000 cycles). • The response generated by CPs can be utilized to monitor changes in the mechanical device. In recent years, as the electronics industry has driven the development of human civilization, flexible responsive materials have become highly favored in sensing applications. However, most flexible materials are not stable under high-temperature conditions, so only a few flexible responsive materials are suitable for high-temperature and high-strength applications. In this paper, multi-walled carbon nanotubes (MWCNTs) were added as conductive material into poly(amic acid) ammonium salt (PAAS) solutions to prepare MWCNTs/polyimide aerogel-based papers (CPs) by a simple method. The introduction of MWCNTs into the ordered multilayer folded structure of the CPs provided a conductive pathway and improved their thermal stability. When the multilayer folded structure was deformed, the MWCNTs between the layers contacted each other, increasing the number of electron transport channels and providing a larger contact area for the conductive network. When the deformation was removed, the MWCNTs in the interlayer contact zone rapidly separated, providing stable and excellent responsiveness at high temperatures (CP-2: ΔR/R 0 value of up to −0.45 at 300 °C) and favorable stability after 1000 cycles (CP-2: RV retention of 92.4 % at 25 °C and 80.5 % at 300 °C). Therefore, the prepared CPs have great application prospects in the fields of high-temperature mechanical device monitoring, sensing, and alarms. [ABSTRACT FROM AUTHOR]

Electron/phonon heat co-transfer, dielectric/magnetic dual loss, and 2D interlinked frameworks codetermine the ultrawide absorption bands, high thermal conductivity, and excellent electrical insulation of CF/M/C (M = Co, Ni, or Fe/Fe 3 O 4) 2D interlinked frameworks. [Display omitted] • A facile soaking-annealing strategy for CF/M/C (M = Co, Ni, Fe/Fe 3 O 4) 2DIFs. • Precisely modulating the interfaces, porosity, and defects. • Optimizing the thermal, electrical, and EMW absorbing properties. • Revealing the synergistic enhancement mechanism. Reasonable design of protective multifunctional materials is highly required for the safety protection of devices/personnel from electromagnetic radiation and heat damage in the 5G/6G era. Herein, a simple soaking-annealing route was adopted to carbonize filter paper into 2D interlinked carbon fiber frameworks inlaid with magnetic nanoparticles, and the products were referred to as CF/M/C 2DIFs (M = Co, Ni, or Fe/Fe 3 O 4). The concentration and type of metal ions as well as the annealing temperature of the CF/M/C 2DIFs were controlled to precisely modulate their composition, porosity, and defects. Results show that the CF/Co/C 2DIFs produced under T a = 600 °C and [Co2+] = 0.45 mol/L exhibit high thermal conductivity (2.931 ∼ 3.167 W/m·K) at small loads (10 ∼ 30 wt%) owing to not merely the presence of 2D interlinked path for electron/phonon heat co-transfer but the reasonable control of interface/defects for weakening phonon/electron defect/interface scattering. Also, the CF/Co/C 2DIFs can attenuate microwaves over a broad frequency range via dielectric/magnetic dual loss and 2DIFs, which boosts their loss ability and matching performance. The excellent performance in both heat dissipation and EM wave absorption proves that the CF/M/C 2DIFs can be a promising candidate for next-generation electronic packaging materials in heat management, military, and aerospace fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multi-layer forming technology can integrate triboelectric material with electrode. • The all CPTENGs can exhibit excellent humidity, acid and alkali resistance. • The CPTENGs can yield a V OC , I SC and power density of 227.1 V, 6.9 μA and 520 mW/m2. • Matching CPTENGs with P-ZISC can obtain a self-charging power system (PSCPS). • The PSCPS can drive some miniaturized electronics for a long time. Triboelectric nanogenerators (TENGs) are regarded as a promising technology to drive the development of flexible/wearable electronics and self-powering sensor. Application of cellulose paper as the triboelectric positive materials makes TENGs more environmentally friendly. However, the limited output performance and stability in harsh environments and oxidation and corrosion of the metal electrodes have limited the practical application of cellulose paper based triboelectric nanogenerators (CPTENGs). Here, we have integrated cellulose paper-based triboelectric material and electrode in one sheet by using multi-layer forming technology in paper industry; the upper triboelectric layer shows excellent triboelectric positive performance, hydrophobicity and acid and alkali resistance, while the bottom electrode exhibits promise conductivity. The all CPTENGs can yield a maximum open-circuit voltage (V OC) of 227.1 V, a short-circuit current (I SC) of 6.9 μA. Furthermore, the V OC values of the all CPTENGs increase from 0.02 V to 225.1 V at the load resistance of 100 Ω∼10 GΩ; and a power density of 520 mW·m−2 is also obtained at a load resistance of 30 MΩ. Moreover, the V OC of CPTENGs not only retains up to 78 % of its initial value at a high relative humidity of 90 %, but also almost maintains unchanged in a wide range of the pH environment (pH = 1∼13). More importantly, the CPTENGs can be readily matched with paper-based zinc supercapacitor (P-ZISC) to act as an all paper based self-charging power system (PSCPS). The PSCPS is capable of driving various miniaturized electronics, such as electronic watch, temperature/humidity indicator, demonstrating its potential application in a sustainable power source for portable and green electronics. [ABSTRACT FROM AUTHOR]

[Display omitted] • FeCu@BC catalysts were synthesized using a simple one-step pyrolysis method. • FeCu@BC 600-2 exhibited good magnetic separation ability and excellent reusability. • The synergistic effect of Fe 3 O 4 , Cu0 and Biochar maintains high RhB removal. • Key ROS involves •OH at pH 3, and •OH and 1O 2 at pH 7, respectively. • sp2 C = C in biochar and Cu(I) from Cu0 facilitated the reduction of Fe(III) Treating the wastes generated from pulp and paper mills, such as black liquor and Fenton sludge is challenging. In this study, the biochar-supported Fe-Cu bimetallic catalysts were synthesized by a one-step pyrolysis method using Fenton sludge as iron source, acid-precipitated black liquor (APBL) as carbon source and copper nitrate as copper source. The catalysts were used to remove rhodamine B (RhB) dye from aqueous solution by Fenton-like reaction. The optimal catalyst (FeCu@BC 600-2) was pyrolyzed at 600 °C with an Fe/Cu mixing ratio of 2 and consisted of mesoporous biochar supported nanoscale Fe 3 O 4 and Cu0. It had a specific surface area of 104.6 m2·g−1 and a saturation magnetization of 33.3 emu·g−1. In the FeCu@BC 600-2 /H 2 O 2 system, RhB dye (10 mg·L-1) was completely removed within 60 min at acidic pH (initial pH 3, 0.2 g·L-1 catalyst, 1 mM H 2 O 2) or 6 h at neutral pH (initial pH 7, 0.25 g·L-1 catalyst, 25 mM H 2 O 2) at 30 °C. Moreover, the FeCu@BC 600-2 exhibited good magnetic separation ability, low metal leaching, excellent reusability and broad applicability to other synthetic dyes. The dye removal mechanism involved the synergistic effect of adsorption and catalytic oxidation (especially heterogeneous catalytic oxidation). At acidic pH, RhB degradation was due to •OH radical, which was generated from the activation of H 2 O 2 by ≡Cu(I) or Cu(I) oxidized from Cu0 and ≡Fe(II) in Fe 3 O 4. At neutral pH, RhB degradation was mainly due to •OH and 1O 2 with the former being produced by ≡Cu(I) and ≡Fe(II). Furthermore, Cu(I) oxidized from Cu0 and the active functional groups (such as sp2 C = C) in the biochar facilitated the reduction of Fe(III) to Fe(II), resulting in a high catalytic oxidation efficiency. [ABSTRACT FROM AUTHOR]

• Three-dimensional WO 2 /MoO 2 @P, N-CNTs were prepared by the Self-template method. • Highly conductive and hollow structure of WO 2 /MoO 2 @P, N-CNTs avoided aggregation of NiCo-LDH. • IMSC devices were prepared by fully screen-printed technology. • IMSCs demonstrated excellent energy density (0.0590 mWh cm−2), cycling stability (100% capacity retention after 10,000 cycles) and mechanical stability (lighting the bulb under extremely distorted conditions). In-plane micro-supercapacitors (IMSCs) have greater promise for use in flexible wearable electronics than traditional stacked configurations due to their ease of integration and conformability. Nickel-cobalt layered double hydroxide (NiCo-LDH) has garnered significant interest as a stellar material for supercapacitors because of its affordable price, regular morphology, and high theoretical capacity. Unfortunately, the intrinsic poor conductivity of LDH materials prevents supercapacitors from achieving long-term stable cycling and the desired energy density. This research successfully applies the self-templated approach to prepare carbon nanotubes (CNTs) with heterogeneous architectures and numerous phase interfaces, thereby mitigating this disadvantage. Carbon nanosheets adorned with WO 2 and MoO 2 nanoparticles assemble the CNT with a typical three-dimensional structure. When combined with LDH in a suitable ratio, the composite electrode's conductivity significantly improves, providing increased capacity and cycling stability. Compared to commercial CNTs, the larger size of the prepared WO 2 /MoO 2 @P, N-CNTs serves a superior supporting and connecting role, thereby preventing the NiCo-LDH from aggregating. Under the best conditions, the composite electrode demonstrates a capacity of 1237 C/g at 1 A g−1 and an optimal capacity retention of more than 92%. For the IMSC devices, the composite materials as the positive electrode achieve an energy density of 0.0590 mWh cm−2, and no capacity degradation is observed after 10,000 cycles. In addition, bending tests have demonstrated the mechanical stability of the IMSCs. Therefore, this strategy of mixing highly conductive WO 2 /MoO 2 @P, N-CNTs can effectively improve the conductivity of the composite material and the mechanical properties of the overall device. Furthermore, this concept can be further extended to the preparation and application of other wearable devices. [ABSTRACT FROM AUTHOR]

• A hydrophobic TENG based on sisal cellulose paper(SCP) was constructed to collect raindrop energy. • Both physical and chemical hydrophobic modification can effectively improve the SCP's dielectric constant. • The hydrophobic SCP-TENG modified by the chemical method is more suitable than the physical method for collecting raindrop energy. • The output electrical signal of SCP-TENG and the raindrop velocity have linear relationship. • The hydrophobic SCP-TENG can be used as raindrop-based sensors. Hydrophobic Sisal cellulose paper (SCP) was obtained by surface modification of SCP via physical adsorbing polymer and chemical grafting monomer, respectively. The influence of surface modification conditioning on the hydrophobicity, dielectric constant and dipole moment of the SCP was investigated. The results showed that the hydrophobicity and dielectric constant of the modified SCP increased with the concentration and amount of the modifiers. The output electrical performance of the TENGs assembled by the two types of hydrophobic SCP for rain energy collection was compared. The output electrical performance of the chemically modified hydrophobic SCP-TENG is higher than that of the physical modified. The maximum power density of the former reaches 8.2 mW/m2. Furthermore, based on the linear relationship between the output performance (output voltage intensity and output current intensity) of hydrophobic SCP-TENG and the droplet velocity, a raindrop-based sensor based on hydrophobic SCP-TENG was successfully constructed and estimated. [ABSTRACT FROM AUTHOR]

• A novel bimetallic nanozyme (COF Fe/CoP-Ph) displayed excellent triple-enzyme mimetic activities. • The multiple enzyme-driven cascade catalysis strategy was proposed. • The colorimetric determination of malathion was achieved without the addition exogenous H 2 O 2. • A smartphone POCT analysis platform with integrated paper chip sensors was developed. Enzyme-induced biological cascade catalysis can achieve selective and efficient transformations of substrates in vivo. Thus, the biomimetic cascade systems have attracted much attention in biological detection on account of their ingenious strategies for signal conduction and amplification. In this study, a porphyrin-based covalent organic framework (COF Fe/CoP-Ph) with bimetal-nitrogen-coordinate centers (M − N 4) were constructed via Schiff base reaction. The synergistic effect of the highly exposed M − N 4 bimetallic active sites and the unique topology overcame the self-limitation of nanozyme, resulting in a significant enhancement of the triple-enzyme mimetic activities of COF Fe/CoP-Ph , namely oxidase (OXD)-, peroxidase (POD)-, and catalase (CAT)-like activities. Simultaneously, a multiple enzyme-driven cascade catalysis strategy for signal amplification was proposed utilizing the OXD- and POD-like mimetic mechanisms of COF Fe/CoP-Ph , enabling the colorimetric determination of malathion without the addition exogenous H 2 O 2. The established colorimetric sensor exhibited an exceptional linear relationship within the range of 1–18 μM and a low detection limit of 11 nM. Subsequently, a portable smartphone platform was developed by integrating paper chip, facilitating successful malathion point-of-care testing (POCT) in real samples. This work not only creates a bimetallic COF nanozyme and establishes an efficient cascade amplification strategy, but also introduces a novel design approach for development of a low-cost and user-friendly POCT method. [ABSTRACT FROM AUTHOR]

[Display omitted] • A laser-derived paper-based three electrode system was fabricated. • The electrodes were thoroughly characterized physically and electrochemically. • The multi-functional sensing ability of the fabricated electrodes was demonstrated. • The chemically engineered electrodes offered great reproducibility and reliability. • Real sample assessment included small molecules, free radicals, and macromolecules. The demand for eco-friendly, disposable, and affordable electrochemical sensors stimulates the fabrication of laser-directed paper-based electrodes. This work reports the fabrication of laser-derived patterns on the paper substrate and its multi-functional sensing applications. For this, a computer-aided design (CAD) software-driven computer numerical control (CNC) manufacturing method was developed to engrave a three-electrode design on a paper substrate. The fabricated L aser- D irected e lectrochemical P aper A nalytical D evice (LD-ePAD) was thoroughly characterized by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), contact angle analysis, electrochemical impedance spectroscopy (EIS), and the cyclic voltammetry (CV). After that, we demonstrated the multi-functional sensing ability of the LD-ePADs by detecting diverse model analytes, including small molecules (i.e., lead ions [Pb2+]), free radicals (i.e., peroxide [H 2 O 2 ]), and macromolecules (i.e., Alkaline phosphatase [ALP]). Upon investigation, it exhibits a fair detection limit of 5.19 (±0.21) µM for Pb2+, 48.66 (±0.31) µM for H 2 O 2 , and 0.48 (±0.02) U/L for ALP. The LD-ePADs' outstanding repeatability, stability, abundance of catalytic active sites, remarkable tunability, and potential for nano-bioengineering emphasized their tremendous commercial feasibility. To the best of our knowledge, this is the first study to use controlled one-step laser direct engraving to fabricate a three-electrode setup on a paper-substrate that can sense three heterogeneous molecules electrochemically. [ABSTRACT FROM AUTHOR]

[Display omitted] • Five new anti-counterfeiting models have been developed using PDLC. • The electro-optical performance with voltage (33.35 V), high contrast (234.06) and response time 11.6 ms. • Combined decoding mode of fluorescent color is not counterfeitable. • The pixel-point anti-counterfeiting mode that is difficult to counterfeit. • The prepared color electronic paper is directly applied to real life. Currently, polymer-dispersed liquid crystal (PDLC) exhibits great potential in anti-counterfeiting and display device applications, but they still have serious disadvantages of poor stability, small voltage-variable color range, low recognition rate, long response time and single-color variation. In this work, the developed novel multiple modulated anti-counterfeiting modes that combined red, yellow and green fluorescent colors and voltages by using the modification strategy of PDLC. A series of anti-counterfeiting PDLC films with multicolor-modulated decoding modes were prepared by introducing fluorescent materials with different emission wavelengths into PDLC. In order to further enhance anti-counterfeiting ability, the model of the dynamic change of micrometer-sized pixel points under different voltages was developed, which greatly increased the difficulty for PDLC being counterfeited. For display application, our developed PDLC-based flexible electronic papers with single- and multi-pattern displays exhibited dynamic change of patterns that could be intelligently adjusted. Noteworthily, the electronic paper had a fast response time (11.6 ms) and high contrast ratio (234.06). Furthermore, the prepared flexible electronic paper served as a billboard for supermarkets that could dynamically regulate real-time prices. In short, the developed PDLC flexible films with multiple anti-counterfeiting and coding modes will have great promising in anti-counterfeiting and display device applications in real life. [ABSTRACT FROM AUTHOR]

[Display omitted] • A rapid and sensitive paper-based colorimetric sensing array for full-content ethanol detection is developed. • The sensing array is fabricated via inkjet-printing diacetylene monomers on A4 paper followed by photopolymerization. • The sensing array displays distinct color difference patterns for diverse ethanol contents. • The sensing array is applicable for discrimination and authentication of ethanol content in real samples. • A smartphone app is develped and integrared with the array that directly enables read-out of the ethanol content in real samples. The accelerated consumption of ethanol in pharmaceutical, food and fuel industries instinctively actuates the development of simple, portable, reliable and inexpensive sensing method for ethanol content monitoring. Herein, a paper-based polydiacetylene (PDA) sensor array is prepared from four diacetylene (DA) monomers modified with imidazole and its derivates. DA inks derived from the four monomers are directly coated on A4 paper via inkjet printing and converted to PDAs by UV irradiation with high stability and uniformity. The printed PDA sensors show solvent induced irreversible color transition upon exposure to organic solvents and water. The diverse colorimetric responses integrally provide unique color change patterns which are capable of distinguishing 11 distinct solvents including ethanol and water. The pattern-based sensing performance further promotes the fabrication of spot-matrix sensor array that could generate distinct color difference maps towards different ethanol contents with multiple sensing elements and a widely dynamic sensing range from 0 to 100%. Combined with RGB value radar map and principal component analysis (PCA), the sensor array also displays excellent ability of differentiating ethanol content from 5 to 100%. With this proposed method, commercial spirit samples with different ethanol contents or gasolines with different amounts of ethanol are readily distinguished and identified through naked eye and PCA score plot. Furthermore, to facilitate usability, a smartphone app is developed and integrated with the PDA sensor array, which directly enables read-out of the ethanol content in real liquor samples with high accuracy. Considering the simplicity, portability and reliability of the proposed sensing system, this study offers a promising method for point-of-use detection of ethanol content that may find broad applications in terms of quality control, food safety inspection and consumer protection. [ABSTRACT FROM AUTHOR]

• A paper-based assay was developed for real-time, onsite, and dual-signal detection of ATP. • The assay integrated the ATP-responsive ZIF-90 collapse and inhibition effect of ZIF-90 for nanozyme. • The analytical signals combined the distance- and colorimetric- readout. • A paper-based kit was designed to achieve standardized ATP onsite detection. Adenosine triphosphate (ATP) is an important biological biomarker, but its rapid extracellular decomposition poses challenges for on-site detection. We report a paper-based dual-readout viscosity flow sensor enabling rapid, equipment-free quantification of ATP. The assay integrates molybdenum disulfide nanozymes for signal amplification with zeolitic imidazolate framework-90 (ZIF-90) for selective ATP recognition and nanozyme regulation. In the presence of ATP, the intact chitosanase-encapsulated ZIF-90 structure was disintegrated to release chitosanase and thus hydrolyzed chitosan hydrogel, decreasing the viscosity of chitosan solution. Moreover, elimination of ZIF-90 inhibitory effect reactivated the catalytic activity of MoS 2 nanozyme, resulting in the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to produce obvious color change. The analytical signals, combining the distance- and colorimetric- readout, were directly displayed on filter paper without further processed. The proposed dual-readout viscosity flow sensor exhibited remarkable sensitivity for ATP detection with detection limits down to 0.038 nM with the distance-readout and 0.057 nM for the colorimetric-readout. Furthermore, we developed an integrated paper kit with a printed scale and color card for standardized on-site analysis without instrumentation. Successful application for ATP quantification in bacterial biofilms and blood samples demonstrates the sensor's strong performance and potential for decentralized testing. [ABSTRACT FROM AUTHOR]

• Honeycomb-like porous paper platform obtained by the laser direct writting. • Simultaneous and accurate monitoring physical and chemical index during exercise. • Exceptional sensitivity (68 mV pH-1) by confined enrichment from cellulose. • On-demand analysis of sweat by joule heating from conducting polymers. Paper-based wearable sensors have gained significant attention in sweat analysis due to their widespread availability, comfortable wearability, and hygroscopic behavior. However, integrating functional components such as the conducting polymers in one sensor to realize the simultaneous and on-demand detection for the physical and chemical indexes compromises their stable performance under operation due to mismatch among various functional parts. We report a stable, multifunctional, and scalable paper-based flexible sensing platform for improved performance for in-situ sweat stimulating and analyzing of sweat as well as the monitoring of body motion. The welded honeycomb structure of composite paper formed in direct laser writing can provide a reversible and precise response in resistance during bending. The internal confined space containing the bacterial cellulose can induce an electrostatic enrichment of hydrogen ions in sweat, thus enhancing the pH-sensing sensitivity (68 mV pH-1). This spatial separating design for the two detections can further isolate the interfering, thus enabling the simultaneous and highly sensitive analysis of pH and movement. In addition, the controlled joule heating effect and the nano-fluid channels of the papers can help generate and rapidly transfer the sweat, further facilitating an on-demand and rapid responsive detection. [ABSTRACT FROM AUTHOR]

Time-resolved multicolor dynamic anti-counterfeiting was achieved by exploiting the stimuli-response properties and lifetimes differences between NOCQDs and NCQDs, realizing the 5D information encryption in all five stimulus-, pattern-, time-, and color-dependent codes. [Display omitted] • Through precise regulation, two kinds of carbon quantum dots (CQDs) were prepared. • The color of afterglow is dependent on excitation wavelength. • Information encryption and dynamic identification were realized in 5D mode. Multi-stimuli responsive multicolored room-temperature phosphorescent (RTP) carbon quantum dots (CQDs) have recently attracted considerable attention, owing to their potential applications in advanced dynamic anti-counterfeiting. The design and development of carbon dots that exhibit both stimulus response characteristics and multicolor RTP emission remains a significant challenge in the field. In this work, we present a novel approach to control the dynamic phosphorescence color and stimulus response properties of CQDs coated on paper by fine-tuning the surface functional groups of the CQDs. Specifically, histidine and 2,4,6-triaminopyrimidine was separately used to prepare N, O co-doped CQDs (NOCQDs) and N-doped CQDs (NCQDs), respectively. These CQDs were further coated on filter paper substrates to achieve water and heating cascade stimulus–response RTP. These stimuli-responsive properties of NOCQDs can be modulated by deprotonating their surface oxygen-containing groups. Eventually, we achieved time-resolved multicolor dynamic anti-counterfeiting by exploiting the stimuli-response properties and lifetimes differences between NOCQDs and NCQDs, realizing the 5D information encryption in all five stimulus-, pattern-, time-, and color-dependent codes. These findings highlight the potential of NOCQDs as advanced anti-counterfeiting materials and lay a foundation for further exploration into the synthesis and properties of CQDs with tunable stimuli-response features and RTP emission. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mercerization allows poly(butylene succinate- co -adipate) (PBSA) oligomer pervasion. • Introduction of the PBSA oligomer bridges the gaps between coating layers. • High-molecular-weight PBSA coating enhances gas/moisture barrier performance. • PBSA/paper composite exhibits deformation resistance under repeated external forces. • All the ingredients constituting the composite are fully bio-based and compostable. Currently, the world is facing a major plastic waste problem. Poly(ethylene terephthalate) and polyolefins are primary base materials in the beverage packaging industry, constituting a significant portion of plastic waste. These materials are often processed as multilayered films to meet high-barrier requirements, rendering their recycling difficult. Furthermore, these petroleum-based plastics persist in landfills without undergoing degradation. Accordingly, herein, we developed compostable plastic/paper composite-based bottles that can replace non-degradable plastic bottles. Crystalline structure of bio-based paper was rearranged by mercerization that modifies the cellulose surface to enhance its pervasive ability with poly(butylene succinate- co -butylene adipate) (PBSA). Introduction and combination of the oligomer and polymer states of PBSA facilitated strong paper-polymer interactions and resulted in superior gas/moisture barrier properties. Unlike the cases of conventional paper-based containers, which are prone to deformation under external forces, the flexible yet robust coating layer of this composite provides resistance to deformation, minimizing deterioration of properties under repeated bending forces. Moreover, all ingredients used in this composite are fully bio-based, and the composite demonstrates approximately 70 % decomposition during an 18-week composting test. Given its significant potential to contribute to the realization of a plastic-free lifestyle in the near future, conducting comprehensive evaluations on biodegradability and toxicity in real environments remains as the crucial step towards the successful commercialization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe-containing waste (paper mill sludge, PS) was pyrolyzed in the N 2 atmosphere. • Fe in PS changed into Fe0 during pyrolysis to form Fe0-carbon composite (PS/BC-750). • PS/BC-750 exhibited high adsorption capacity for Se(VI) and Se(IV). • Se(VI) and Se(IV) were chemisorbed onto different binding sites on PS/BC-750. This study aimed to fabricate zero-valent iron (Fe0)-loaded biochar from an industrial waste and further demonstrate its applicability as an environmental medium to remove Se(VI) and Se(IV). The biochar (PS/BC-750) was produced via the pyrolysis of paper-mill sludge under N 2 atmosphere. The characterization revealed that PS/BC-750 has a porous carbon structure embedded with reduced Fe phases (Fe0 and FeO). The adsorptive removal of Se(VI) and Se(IV) by PS/BC-750 was highly dependent on pH condition and progressively decreased with the pH increase. The adsorption kinetics of Se(VI) and Se(IV) reached equilibrium within 1440 and 60 min, respectively, following a pseudo-second-order kinetics. Se(VI) and Se(IV) adsorption isotherms fit to the Freundlich and Langmuir models, respectively, highlighting the importance of chemisorption in the adsorption processes. X-ray photoelectron spectroscopy and competing anions experiments revealed that Se(VI) was adsorbed mainly on the Fe phases while Se(IV) was adsorbed on both Fe phases and carbon surface by specific binding mechanisms, with those adsorbed on Fe phases being subsequently reduced to Se0. The results demonstrated that the pyrolytic process can be of a viable platform for converting Fe-containing waste materials into environmental media with a wide application potential. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gentle power of laser was used to do surface modification of paper substrates. • Effects of different types of lasers including CWL, NS, and FS were studies. • Physical and chemical changes of laser-ablated paper were investigated. • Aldehydes were produced by laser ablation and raised the paper's chemical reactivity. • Aldehydes-related color chemical reactions were performed with acoustofluidic PADs. Paper-based analytical devices (PADs) have rapidly thrived in the last decade for their easy operation and rapid response. However, because of its low chemical reactivity, it's still challenging to endow the paper substrate with more functions and expand its application field. Here, this work leverages lasers to do surface modifications of paper to raise its chemical reactivity. A gentle power of laser was utilized to ablate a part thickness of the paper. The effect of laser types was studied, including continuous-wave, nanosecond, and femtosecond lasers. Continuous-wave laser caused severe photothermal effects and produced more pyrolytic oil. The physical changes including mechanical strength and fluid wicking were studied. The chemical changes were analyzed by XPS and FTIR. Because of the produced aldehydes by laser ablation, the laser-modified papers were endowed with more functions and we experimented with aldehyde-related color reactions on them, which might promote the color printing industry. In addition, to fully exploit the produced aldehydes, our recently developed acoustofluidic PADs were employed for flow intensification and homogeneous mixing. This work demonstrates an economical and effective method for a new type of functional paper substrates which holds potential for various fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • First proposal for high value-added reuse of industrial waste photosensitive polyimide. • Developed fully crosslinked ink to maintain a high shape fidelity (shrinkage <5 %). • Balanced strength and toughness by combining long/short-chain crosslinkers. • Extended 2D photolithography of w-PSPI to maskless 3D printing. In the mass industrial production process of polyimide photoresists, waste generation is inevitable due to unqualified molecular weights, inappropriate ionic content of resins, or storage expiration. Consequently, the recycling and reuse of waste photosensitive polyimide (w-PSPI) is a growing concern in both scientific and industrial communities. In this work, w-PSPI was explored to prepare photocurable, fully crosslinked inks for digital light projection technology (DLP). For this purpose, suitable photoactive solvents and crosslinking agents were first screened to overcome the issue of large shrinkage caused by solvent volatilization. The formation of cross-linked network structures during DLP processing and subsequent imidization was also investigated. As a result, a polyimide DLP ink with minimum size shrinkage (less than 5 %) was proposed. For a given active solvent, the mechanical behavior and heat resistance of DLP-formed objects were significantly influenced by the ratio of short-chain and long-chain crosslinkers and the imidization temperature. By optimizing ink composition and imidization temperature, the DLP-formed objects showed high heat resistance (T d 5 > 385 °C, T g > 150 °C) and balanced mechanical properties of strength and toughness (Modulus ≥1 GPa, elongation at break >5 %). This w-PSPI ink has been successfully utilized to manufacture several complex 3D structures and vertical 3D microarrays with 100-µm on a limited-resolution DLP printer. This study not only points the direction for the high-added utilization of w-PSPI but also demonstrates the potential for expanding PSPI application from 2D lithography to 3D micro-manufacturing. [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly active 2e-WOR electrocatalyst was prepared by modifying CFP with SAMs. • SAMs modified CFP achieves a high H 2 O 2 yield of 79.8 μmol min−1 cm−2 at 2.1 V. • SAMs modification enriches the 2e-WOR active site and reduces the OER active site by modulating the ΔG*OH. • Carbon atoms adjacent to O=C-M are active sites for efficient 2e-WOR. • O=C-M are rooted from the reaction between the functional group on CFP and SAMs. Two-electron water oxidation (2e-WOR) is an attractive method for the electrosynthesis of hydrogen peroxide (H 2 O 2). However, its practical application is limited by the viable 2e-WOR catalysts that can ensure high selectivity and high H 2 O 2 yield. In this paper, a highly active 2e-WOR electrocatalyst was prepared by modifying carbon fiber paper (CFP) with a self-assembled membrane (SAMs). The SAMs modified CFP can achieve an H 2 O 2 yield of 79.8 μmol min−1 cm−2 and an H 2 O 2 selectivity of 82.5% at a low potential (2.1 V vs. RHE). The DFT calculation reveals that SAMs modification can modulate the *OH binding energy of the active site on CFP, thus leading to a significantly improved selectivity and production rate of H 2 O 2. Moreover, the 2e-WOR performance is found to be independent of the functional tail groups of SAMs because the electron transfer during the 2e-WOR occurs through direct electron transfer via the carbon atoms adjacent to the O=C-M on carbon fiber rather than the well-known electron tunneling through SAMs. This study provides a new strategy for surface modification of 2e-WOR carbon-based catalysts and opens a new way for efficient electrosynthesis of H 2 O 2. [ABSTRACT FROM AUTHOR]

An ultra-sensitive paper-based molecularly imprinted sensor for detection of H5N1 was described. The results can not only be detected quantitatively by fluorescence, but also can be directly read with naked eyes under visible light or ultraviolet light within 10 min. With naked eye detection, its sensitivity is obviously better than that of commercial kits. In particular, the cost of the sensor is cheap (Original size: RMB 1.53 Yuan each; Smaller size: RMB 0.08 Yuan each), which is beneficial to application. [Display omitted] • Paper-based molecularly imprinted sensor; • Ultra-sensitive detection of H5N1 (LOD, 0.58 fM); • Rapid visual detection of influenza H5N1 within 10 min; • More intuitive and sensitive results than commercially available kit; • Low cost (Original size, 1.53 yuan/piece; Smaller size, 0.08 yuan/piece). The rapid detection of pathogens is important to the control of epidemics. Here, a paper-based molecularly imprinted sensor has been developed for the visual detection of influenza H5N1 virus. Firstly, the paper-based molecularly imprinted was prepared by a sol–gel reaction. Then, H5N1 ∼ Apt was covalently bound to the surface of the ZIF-8-NH 2 coated with rhodamine B (RhB) through an amide bond, to produce the fluorescent and colorimetric probe ZIF-8-NH 2 @RhB ∼ Apt. When H5N1 and ZIF-8-NH 2 @RhB ∼ Apt are added to the paper-based MIPs, the H5N1 will be combined with MIPs through the synergistic effects of shape and size compatibility and interaction with the functional groups of the monomers, and ZIF-8-NH 2 @RhB ∼ Apt will bind to H5N1 through its aptamers to form a sandwich structure. The sensor has ultra-high sensitivity and the detection limit is 0.58 fmol/L by using fluorescence spectroscopy. A semi-quantitative signal can also be observed with the naked eye within 10 min. A comparative study showed that direct visual detection was highly reliable, and the sensitivity was better than that achieved with a commercially available kit. Importantly, the paper-based sensor is low in produce cost (Original size: RMB 1.53 Yuan each; Smaller size: RMB 0.08 Yuan each) and is easy to cut, store and carry. This sensor is expected to allow self-service, visual, high-throughput, and real-time virus detection, which is of great significance for epidemic prevention and control. [ABSTRACT FROM AUTHOR]

A practicable strategy for large-scale fabrication of highly flexible, durable, mechanically strong, and flame-retardant MXene-coated aramid paper (MAP) with outstanding EMI shielding and desirable electrical heating performance is proposed, indicating the promising potential applied in strict EMI shielding application scenarios. [Display omitted] • A flexible, durable, and multifunctional MXene-coated aramid paper (MAP) is prepared. • The EMI SE and structure of MAP are regulated by single/dual coating and optional hot-calendering. • MAP exhibits excellent EMI shielding with an EMI SE/t of 422.2 dB mm−1 at a low MXene content (9 wt%). • MAP demonstrates great potential in electromagnetic shielding and thermal management. Undesirable electromagnetic interference (EMI) created by modern electronic devices has detrimental effects on the performance of high-precision electronic devices, information security, and human health. Therefore, lightweight, flexible, robust, and easy-to-fabricate EMI shielding materials with integrated functions are highly desirable to combat electromagnetic pollution. Herein, we report a scalable and facile strategy to prepare a flexible Ti 3 C 2 T x MXene-coated aramid paper (MAP) with high-efficiency EMI shielding and excellent electrical heating performance. The intertwined network by aramid fibers endows the aramid paper (AP) with superior mechanical properties. After selectively single/dual coating with MXene onto AP, the MAP maintains a superior tensile strength of 73.6 MPa and enormous folding endurance of 4156 times. Owing to the exceptional electrical conductivity of MXene, the MAP with a relatively low MXene content (∼9.0 wt%) exhibits excellent overall performance with an EMI shielding effectiveness (SE) of 38 dB and SE/t of 422.2 dB mm−1. It's noteworthy that the EMI SE of the MAP remains almost unchanged (37.4 dB) even after experiencing 5,000 repeated bending cycles. Additionally, the MAP shows satisfactory Joule electric-heating capability (a heating temperature rise of 130 °C at a low driving voltage of 5 V) and excellent flame-retardancy. This work provides a feasible strategy for large-scale production of flexible EMI shielding paper with multifunctional properties for future wearable facilities. [ABSTRACT FROM AUTHOR]

[Display omitted] • A groundbreaking approach was proposed to produce phosphorylated cellulosic paper. • Cellulose phosphorylation by thermo-compression induces a hornification phenomenon. • Hornification increases the paper crystallinity (91%) and thus the overall quality. • Coating the papers with EVA polymer strongly increase their specific properties. • The new phosphorylation approach produced an effective paper for packaging. With the increasing demand for environmentally friendly alternatives to traditional plastic packaging, the development of sustainable cellulosic-based materials has become a strategic research topic. In this concept, a groundbreaking approach was adopted herein to produce phosphorylated cellulose microfibers (CMFs)-based paper packaging via a one-pot preparation step using a thermo-compression process (150 °C under pression for 45 min) in the presence of diammonium hydrogen phosphate ((NH 4) 2 HPO 4 , denoted DAP) and urea. This process involves a chemical mechanism leading to the production of phosphorylated cellulosic paper with a very compacted structure induced by the hornification phenomenon. This phenomenon reveals the formation of additional and irreversible strong hydrogen bonds leading thus to an increase of the materials' crystallinity up to 91%, and to an enhancement of their morphological, thermal stability, flame retardancy, hydrophobicity, water vapor permeability, and mechanical strength properties. To further enhance these properties, and thus their potential applications, the as-produced phosphorylated CMF paper samples were then coated with a thin layer (40 ± 1.11 µm) of poly[ethylene-co-(vinyl acetate)] (EVA) polymer. A comparison of collected properties with those from non-phosphorylated CMFs or from materials prepared using the conventional phosphorylation process clearly demonstrates that the proposed one-pot preparation method led to the production of advanced materials more effective for packaging applications. Overall, the findings associated to this work could be used as a proof-of-concept for the development of sustainable packaging materials, which could be made by following a more efficient and cost-effective manufacturing procedure than current benchmarks. [ABSTRACT FROM AUTHOR]

[Display omitted] • A general metal-ion-modification (MIM) route is invented to execute wettability transition of lignocellulose materials. • Approximately 3 mg of metal ions (e.g., Fe3+ and Zr4+) can turn 1 g hydrophilic of kraft pulps to hydrophobic ones. • Metal coordination-induced self-assembly of nanofibrils is responsible for the wettability transition of lignocellulose. • MIM-derived hydrophobic paper and tableware are economic feasible, safe, biodegradable, and recyclable. Inherent hydrophilicity and poor water resistance prevent using lignocellulosic materials as green plastic alternatives to fossil fuel-based plastics. Here, we report a facile metal-ion-modification (MIM) route, swelling with aqueous metal ion solutions, and drying to convert conventional hydrophilic paper and wood pulp into biodegradable hydrophobic paper and tableware without the addition of hydrophobic sizing chemicals/materials. Metal ions such as Fe3+ and Zr4+ can coordinate with pulp fibers' polar groups (i.e., OH, C O, and COOH) that induce self-assembly of their surface fibrillated "hairy" cellulose nanofibrils to form a more compact structure with fewer available OH groups for water sorption. This decreases the surface energy of pulp fibers and increases their hydrophobicity and water resistance. Only ∼3 mg of metal ions is needed to induce the wettability transition in 1 g of kraft pulp, resulting in hydrophobic paper and tableware with water contact angles (WCAs) of 120–140°. The coordinated Fe3+ and Zr4+ are stable, with negligible metal leaching during use, allowing the hydrophobic paper and tableware to be used for food packaging. This MIM technique can be integrated into the existing paper-making process for the scalable production of hydrophobic papers and tableware, providing an alternative route for developing sustainable and biodegradable plastic counterparts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Paper mill sludge-based biochar (PSBC) is synthesized for PDS activation. • High BPA removal efficiency can be achieved by the PSBC950/PDS process. • Both radical and non-radical pathways are involved in BPA degradation. • Fe(Ⅱ), O V , C O, and graphitized sp2-C with defects were identified as active sites. • The enhancement effects of C O and defects to the electron transfer were confirmed. Paper mill sludge generated from the pulp and papermaking industries has inherent iron and carbon contents. Herein, the biochar derived from paper mill sludge (PSBC) was synthesized via simple pyrolysis processes and applied as an efficient persulfate (PDS) activator for the removal of Bisphenol A (BPA) in water. The unique properties of PSBC endowed it with multiple active sites including Fe(II) species, oxygen vacancy, C O, and graphite sp2-C with defects, owing to which, the PSBC/PDS process presented satisfactory performance with BPA removal efficiency up to 98 % within 60 min. Both of the radical and non-radical pathways were revealed to be involved in the BPA degradation. Based on the results of theoretical calculation, the existences of some special structures in PSBC effectively facilitated the electron transfer process of PDS activation. The process also exhibited a high anti-interference capability to coexisting substances and the universality toward various organic contaminants degradation. And the used PSBC can be recovered by simple thermal treatment. This work provided a promising heterogeneous PDS activator with plentiful active sites and satisfactory efficiency, which can be beneficial to the cost reduction of wastewater treatment and promotes the application of paper mill sludge in the area of environmental remediation. [ABSTRACT FROM AUTHOR]

Various organic and inorganic hazardous substances are commonly originated during the processing of virgin or recovered fibers (RCFs), when the pulp and paper (P&P) are produced. Hence, pulp and paper industry (PPI) strongly need to employ advanced waste treatment processes as a powerful tool to comply with the stringent environmental regulations in one hand, and to increase their profitability in the current declining P&P markets, on the other hand. Among the treatment alternatives, anaerobic digestion (AD), is an interesting cost-effective alternative with a small environmental footprint and has been increasingly adopted by the PPI to reach this goal. However, the application of AD to deal with wastes generated in P&P mills has been restricted due to a number of limitations, regarding the anaerobic reactor design and the operating conditions. Hence, the optimization of the AD performance would be a crucial step in order to increase the economic benefits, and also to satisfy the strict environmental protection standards. To this end, this paper presents an overview on the current state of the developments associated with AD treatment of P&P mill wastes to assess the applicability of this treatment process for the management of this type of complex wastes. In this context, suggestions are provided to maximize both biogas production and removal efficiency, focusing on the relationship between waste composition and reactor design and operational conditions, which will enhance methane capture and contribute to prevent global warming. [ABSTRACT FROM AUTHOR]

[Display omitted] • Paper-based cascade sensitized structure of CuInSe 2 /Cu 3 (BTC) 2 /Y:ZnO was assembled. • The entropy-driven SDA propelled DNAzyme roller amplification strategy was designed. • Surface plasmon resonance-enhanced cascaded sensitization effect was proposed. Herein, the surface plasmon resonance (SPR)-enhanced cascaded sensitization effect of CuInSe 2 /Cu 3 (BTC) 2 /yttrium doped ZnO (Y:ZnO) photosensitive structures were integrated on lab-on-paper photoelectrochemical (PEC) biosensing platform for the ultrasensitive detection of microRNA-21 (miRNA-21) based on entropy-driven strand displacement amplification (SDA) propelled DNAzyme roller amplification strategy. The Y element doping equipped the paper-based Y:ZnO nanorods with enhanced PEC performance, which was further cosensitized with Cu 3 (BTC) 2 metal-organic framework (MOF) and CuInSe 2 quantum dots (QDs), giving a cascaded sensitization effect for generating a robust and stable photocurrent signal. The SPR effect between CuInSe 2 QDs and Au nanoparticles (NPs) was activated with the aid of entropy-driven SDA propelled DNAzyme roller amplification-induced conversion of target miRNA-21 to Au NPs-labelled track DNA (track DNA-Au), which could effectively promote the photogenerated carrier separation and transfer of CuInSe 2 /Cu 3 (BTC) 2 /Y:ZnO cascade sensitized structures via hot-electron transfer mechanism, further enhancing the photocurrent signal. Based on this designed "signal-on" mode, the quantitative detection of miRNA-21 was achieved with high sensitivity, good specificity, and excellent practicability, which provided a promising model for developing lab-on-paper diagnostic tool for biomedicine. [ABSTRACT FROM AUTHOR]

[Display omitted] • A chitosan modified filter paper separator is designed for aqueous zinc batteries. • Chitosan allows preferential adsorptions of ions in ZnSO 4 electrolytes. • Side reactions at Zn electrodes are inhibited, and uniform Zn deposition is realized. • Zn electrode presents 2900 h cycle life, and coulombic efficiency reaches 99.6%. • The Zn||MnO 2 battery achieves 98.4% capacity retention after 1000 cycles. The electrochemical performance of Zn metal anode in aqueous batteries is serious challenged by side reactions and dendrite growth. Separators are important cell components, which directly interact with electrolyte species and present potential solutions to regulate Zn anode performance. Herein, we modify the conventional filter paper separators by coating chitosan on the fibers. The hydroxyl, amino and ether groups on chitosan allow preferential adsorptions of proton, zinc ion and sulfate in ZnSO 4 aqueous electrolytes. Proton adsorption suppresses the proton activity, which inhibits corrosions and hydrogen evolution reactions at Zn electrode. The interactions of zinc ion and sulfate with chitosan regulate the ion transport manner and enlarge Zn2+ transference number, which ensures homogeneous Zn nucleation and growth. With the application of chitosan modified filter paper separators, the Zn electrode presents a long cycle life of 2900 h. A high coulombic efficiency of 99.6% is achieved. The chitosan modified separators also enhance the capacity retention of Zn||MnO 2 batteries from 52.8% to 98.4% over 1000 cycles. Our work presents an effective separator regulation approach for high-performance aqueous Zn batteries. [ABSTRACT FROM AUTHOR]

• A selective paper-based antibody-free COVID-19 assay. • The enzymatic activity of the virus-related 3CL protease is applied for detection. • All our tests were validated against PCR tests displaying similar selectivity and sensitivity. • Our sensor displays an ultrafast detection turnover of ca. 1 min. • No instruments are required to perform the simple colorimetric diagnosis. COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 has led to high mortality worldwide, with social and financial effects expected to persist for years to come. Since asymptomatic individuals cause a large portion of transmission, actions taken to curb the COVID-19 pandemic mostly rely on procedures aimed at detecting viral-related molecules in infected carriers. Currently, leading available detection methods fall short in reliability or point-of-care mass screening applicability. Here, we present an unprecedented antibody-free smart pH paper-based seconds-long detection platform against the virus-related enzyme 3CLpro as a saliva biomarker of SARS-CoV-2 infection. The selective proteolytic activity of 3CLpro is directly detected from native saliva using a peptide substrate-embedded pH-paper platform. 3CLpro presence in infected individuals leads to an ultrafast pH-drop in the paper matrix, thus leading to a sharp color change as direct means of detection. Ultrafast detection, simplicity, no requirement of surface chemistry by sensitive biomolecules, long-term stability, and point-of-care compatibility for COVID-19 mass screening were demonstrated. Forty-two subjects were tested, exhibiting highly sensitive and specific detection of SARS-CoV-2 infection. Finally, we foresee that this universal approach could be implemented for the multiplexed detection of other viral infections by detecting specific viral proteases. Importantly, since our approach does not require immune-specific antibodies for specific detection, the overall platform is extremely cost-efficient, less than 2 USD cents per assay, and suitable for the worldwide mass screening of viral infections, particularly in remote and developing world locations. Moreover, we propose an extremely easy-to-use and produce practical test strip design. [ABSTRACT FROM AUTHOR]

[Display omitted] • Robust pH/moisture sensitive smart packaging paper (CS/CMC-Anth) was fabricated. • The anthocyanin release amount in distilled water was reduced about 58.72%. • The tensile strength of colorimetric paper was reinforced from 9.51 MPa to 55.68 MPa. • Freshness of fruits and pork can be real-time detected by discernible color change. • Shelf life of fruits can be extended at least one week under ambient conditions. Intelligent packaging system for real-time visual monitoring the freshness of foods plays a key role in the field of food safety. Employing biopolymer as matrix and natural anthocyanin as pH sensing indicator has arouse growing interest for freshness detecting in recent years. However, the anthocyanin migration phenomenon and relatively poor mechanical strength of film restricted the practicability of biopolymer-based smart packaging system. In this work, we constructed a sort of pH/moisture sensitive chitosan (CS)/carboxymethyl cellulose (CMC) coacervates containing anthocyanin (cyanidin cation type, extracted from blueberry) on cellulosic paper by facile layer-by-layer assembly, in which anthocyanin was firmly anchored. The accumulated release amount of anthocyanin in distilled water was reduced from 78.14% to 19.42% compared to pristine CMC-Anth paper. The maximum tensile strength was significantly improved from 9.51 MPa for initial filter paper to 55.68 MPa for (CS/CMC-Anth) 4 colorimetric paper and the compact CS/CMC-Anth bilayer endowed colorimetric paper with excellent structural stability upon folding at least 1000 times. The assembled (CS/CMC-Anth) 4 colorimetric paper delivered response to pH/moisture and can be employed to real-time monitor the freshness of pork and fruits. The integration of intelligent sensor technology and food science will make the food industry present a green, efficient, intelligent, accurate and diversified business model in the future. [ABSTRACT FROM AUTHOR]

• Nacre-like FG/Al energetic paper was designed and prepared. • A significantly enhanced energy and pressure output are obtained. • FG/Al energetic papers shown self-propagate combustion reaction at micro-scale. • The chemical reaction mechanism was distinctly elucidated. • FG/Al energetic paper displayed high flexibility and strain. Developing functional devices requires energetic materials with comprehensive performance including high energy density, excellent chemical reactivity and mechanical properties. Herein, an effective strategy inspired by nacre-like architecture was employed to construct new fluorographene (FG)/nano-aluminum (Al) energetic paper through a vacuum filtration induced self-assembly process. FG/Al energetic paper showed ultrahigh reactivity and high flexibility owing to combined effect of the nacre-like architecture and interfacial interaction. FG/Al energetic paper exhibited significantly enhanced energy output (3257.7 J/g) and self-propagate combustion reaction with high pressure output at micro-scale. Chemical reaction mechanism was distinctly elucidated based on reactive molecular dynamics simulations and the combustion products of FG/Al energetic paper. More interestingly, FG/Al energetic paper displayed high flexibility and strain (5.39%) reported for the first time. The bio-inspired route provides a promising approach to design advanced energetic materials for applications in transportation, aerospace, and military industries. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • An integrated paper-based platform is proposed for the HSA concentration detection. • BCG reagent and HSA concentration is induced albumin-BCG complex for RGB detection. • HAS concentration of 36 real-world human samples are measured. • The results are in excellent agreement of R2 = 0.9912 versus official method. Abstract A rapid analytical platform composed of a paper-based chip (µPB-Chip) and a small analytic box is developed to determine the concentration of human serum albumin (HSA). In this study, a Bromocresol Green (BCG) reagent is dropped into the reaction area of the µPB-Chip, and the HSA concentration was derived from the R (red) value intensity of the albumin-BCG complex formed after a reaction process at 37 °C for 12 min. The effectiveness of the developed method is displayed using albumin concentrations ranging from 0 to 5 g/dL in HSA control samples. The measurement results acquired from 36 volunteer patient’s HSA samples are presented to be in good consistency with those obtained utilizing a conventional assay technique (R2 = 0.9912). Ultimately, the results show that the developed platform provides a convenient, economical and dependable method for HSA concentration detection. [ABSTRACT FROM AUTHOR]

Paper recycling systems based on flotation technologies are not efficient to deink secondary fibers from new printing technologies based on flexographic inks which, even being more environmentally friendly, still present some recycling problems. We have evaluated the efficiency of a biotechnological approach, based on the laccase-mediator system, for biodeinking of three flexographic inks (Blue 1, Magenta HX-E and Red 48:4) in the presence of several pulps (bleached pulp, deinked paper pulp from secondary fibers and pulp from commercial uncoated and coated office paper sheets). Two fungal laccases, one from the basidiomycete Coriolopsis rigida and the other from the ascomycete Myceliophthora thermophila , were used as catalysts in the presence of HBT (1-hydroxybenzotriazole) or methyl syringate, as models of synthetic and natural mediators, respectively. Higher decoloration rates were achieved for Blue 1 and Magenta HX-E than for Red 48:4. The best results were obtained using bleached pulps without additives. Then, to identify the chemical compounds that may hamper enzymatic biodeinking, the influence of several additives on ink decoloration and enzyme activity was tested. Only calcium carbonate slowed down ink decolorization by up to 40%, although it also decreased the mediator assisted enzyme deactivation. In this work, a system to evaluate the efficiency of the laccase-mediator system in biodeinking of flexographic inks in the presence of different pulps and papers has been developed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The chromogenic paper chip was facilely prepared by one-pot synthesis. • The "all-in-one" strategy fundamentally improves the stability and convenience. • Glucose level can be noninvasively detected with "sample in, result out" manner. • A smartphone App was developed for further improving the accuracy and ease of use. Noninvasive glucose detection for diabetes monitoring, in comparison with the conventional finger-prick test that causes inevitable pain, is on demand. Salivary glucose level that possesses a well-established correlation with blood glucose level can be a promising alternative for noninvasive detection, however, the sensitivity and user-friendliness remained to be improved. Herein, an "all-in-one" paper chip was fabricated by one-pot method for sensitive and user-friendly detection of salivary glucose level. Glucose oxidase (GOx) and the chromogenic reagent, luminol, were both in situ encapsulated in a metal–organic framework, ZIF-67, to form the GOx&luminol@ZIF-67@Paper (G&L@ZIF@Paper). Owing to the specificity of GOx and the peroxidase activity of ZIF-67, the paper chips are highly sensitive and specific for glucose with a linear range from 0.2 to 2 mM, and a limit of detection of 0.12 mM (S/N = 3). Moreover, ascribing to the protection and "all-in-one" structure by ZIF-67, the chip is highly stable that maintains the detection performance after storage at room temperature in air for 4 weeks, and this strategy also facilitates the one-pot detection without multiple steps of sampling and incubation. With the assistance of a smartphone application, the glucose level in saliva can be accurately detected with "sample-in-result-out" manner, and the results were highly consistent with those measured by commercial kit. This paper chip is a promising device for daily glucose monitoring, and the highly-integrated strategy provides an innovative resolution for the construction of colorimetric paper chips. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of micro-fibrillated cellulose fibers by a two-step refining process. • Valley beater and a ball mill refining process does not involve the use of chemicals. • Sustainable produced MFCs can be applied to paper-based flexible electronic devices. Cellulose micro/nano-materials are potential substrates for energy storage/ electronics applications. However, developing efficient/cost-effective technologies that can obtain these micro/nano-materials suited for flexible electronics continue to be a challenge. In this study, we report a simple process for extracting micro-fibrillated cellulose fibers from conventional bleached kraft pulp that are particularly applicable to flexible electronics applications. The process is made of two step refining: 1) refining in a Valley beater, and 2) further fibrillation in a ball mill. The Valley beater is to induce fibrillation of pulp fibers as a result of compression and shearing forces. Subsequently, the partially fibrillated cellulose fibers are further subjected to ball milling to obtain micro-fibrillated cellulose fibers (MFCs). These MFCs have a much higher specific surface area than the conventional pulp fibers due to fibrillation and reduction in fiber size, which leads to favorable properties to the as- prepared MFCs network, including high transparence, and high tensile strength. The MFCs paper exhibits excellent transparency of 82% at 550 nm (a significant increase of about 56% for the control), with exceptionally high tensile strength (35.16 MPa). Thanks to the high surface area of these MFCs, silver nanowires (AgNWs) can be well distributed into the MFCs network so that conductive paper with high conductivity was prepared. The MFCs/AgNWs composite paper was then assembled into the paper-based triboelectric nanogenerator (P-TENG) device, which shows excellent performance. The MFCs/AgNWs composite paper- based P-TENG system can also serve as self-powered sensors for monitoring human motions. This work provides a method for the production of micro- fibrillated cellulose fibers that can be applied for the production of flexible electronic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developing a superhydrophobic, kirigami, stretchable pencil-on-paper device platform. • Simultaneously detecting gas, temperature, electrophysiological signals, and providing treatments via thermal therapy and electrical stimulation. • The gas sensor exhibits a large response to NO 2 gas at elevated temperature from self-heating. • The integrated temperature sensor and electrodes accurately detect temperature and electrophysiological signals. • The thermal therapy and electrical stimulation deliver effective means to battle against inflammation/infection and treat chronic wounds. Wearable electronics with applications in healthcare, human–machine interfaces, and robotics often explore complex manufacturing procedures and are not disposable. Although the use of conductive pencil patterns on cellulose paper provides inexpensive, disposable sensors, they have limited stretchability and are easily affected by variations in the ambient environment. This work presents the combination of pencil-on-paper with the hydrophobic fumed SiO 2 (Hf-SiO 2) coating and stretchable kirigami structures from laser cutting to prepare a superhydrophobic, stretchable pencil-on-paper multifunctional sensing platform. The resulting sensor exhibits a large response to NO 2 gas at elevated temperature from self-heating, which is minimally affected by the variations in the ambient temperature and relative humidity, as well as mechanical deformations such as bending and stretching states. The integrated temperature sensor and electrodes with the sensing platform can accurately detect temperature and electrophysiological signals to alert for adverse thermal effects and cardiopulmonary diseases. The thermal therapy and electrical stimulation provided by the platform can also deliver effective means to battle against inflammation/infection and treat chronic wounds. The superhydrophobic pencil-on-paper multifunctional device platform provides a low-cost, disposable solution to disease diagnostic confirmation and early treatment for personal and population health. [ABSTRACT FROM AUTHOR]