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A sensitive immunochromatographic assay (ICA) using time-resolved fluorescence microspheres (TRFMs) coupled with an indirect-labeling mode was developed for simultaneously determining 22 kinds of β-lactams in milk samples. The TRFMs labeled anti-receptor monoclonal antibodies (mAbs) conjugated to penicillin-binding proteins (PBPs) as ternary TRFMs-mAb-PBPs (TMP) nanoscaffolds provide excellent solubility, brightness, and stability. Thanks to the fact that they not only fully expose the binding sites of PBPs, thereby enhancing the biological affinity of PBPs towards the target, but also generated superb fluorescence signals, the versatile TMP manifested unique possibilities as efficient probes for ICA with remarkable enhancement in sensitivity in β-lactams screening. The results showed that the standard curves of the 22 varying β-lactams displayed linearity in their respective concentration ranges (R2 > 0.98), with the cutoff values of 1–100 ng/mL. The constructed TMP-ICA was successfully applied to the analysis of real milk, with consistent results compared with liquid chromatography-tandem mass spectrometry (LC-MS), providing an effective method for sensing β-lactams in food matrices. [ABSTRACT FROM AUTHOR]

We presented a signal amplified lateral flow assay (LFA) based on magnetite nanoparticles (MNPs) labeled dual-probe and applied it in the high sensitive and rapid on-site detection of furazolidone metabolite of 3-amino-2-oxazolidinone (AOZ). The amplified signal benefited from high affinity between two probes of MNPs labeled murine monoclonal antibody (MNPs-MAb) and goat anti-mouse antibody (MNPs-GAMA) and was achieved by the generation of dual-probe network complex. This developed method could realize high sensitive detection of AOZ with a threshold value of 0.88 ng mL −1 and a detection limit of 0.044 ng mL −1 , the sensitivity was at least 10-fold improved than that of the traditional gold nanoparticle based LFA. This facile developed assay was successfully applied for rapid detection of AOZ in milk samples. The proposed method paves a new way for on-site screening of other hazardous substances in food and can be referred in all lateral flow assays. [ABSTRACT FROM AUTHOR]

Small molecules are difficult to detect by conventional gold lateral flow assay (GLFA) sensitively because the test system must satisfy the conflict requirements between enough signal intensity and limited antibody (Ab) amount. In this work, a paired labels recognition (PLR)-based biosensor was designed by utilizing the specific binding of Ab and secondary antibody (anti-Ab) to enhance signal intensity and reduce antibody amount applied in small molecule detection. The PLR amplification system is fabricated by self-assembling the common detection probe, Au-labeled Ab (Au-Ab), and the signal booster, Au-labeled anti-Ab (Au-anti-Ab). Benefiting from this, a powerful network structure can be generated to accumulate numerous gold nanoparticles (GNPs) and thus significantly strengthen the signal intensity of detection. Therefore, a lower Ab amount will be applied to offer adequate signal strength, and further, the limit of detection will be obviously downregulated due to the more effective competition reaction. Using furazolidone (FZD) as a model analyte, we achieve a detection limit of as low as 1 ng mL−1, which was at least fivefold improved over that of the traditional GLFA. Furthermore, the practicality of this strategy was certificated in five different food samples.A paired labels recognition (PLR) amplification system is fabricated by self-assembling the common detection probe, Au-labeled Ab (Au-Ab), and the signal booster, Au-labeled anti-Ab (Au-anti-Ab). In this novel strategy, owing to the recognition of both Ab and anti-Ab labeled on gold nanoparticles (GNPs), a powerful network structure can be generated to accumulate numerous GNPs and thus significantly strengthen the signal intensity of detection. [ABSTRACT FROM AUTHOR]

Portable devices for on-site foodborne pathogens detection are urgently desirable. Lateral flow immunoassay (LFIA) provides an efficient strategy for pathogens detection, however, antibody labeling independence and detection reliability, are still challenging. Here, we report the development of a label-free LFIA with dual-readout using glucan-functionalized two-dimensional (2D) transition metal dichalcogenides (TMDs) tungsten disulfide (WS 2) as detection probes for sensitive detection of Salmonella enteritidis (S. enteritidis). In particular, glucan-functionalized WS 2 , synthesized via liquid exfoliation, are reliable detection antibody candidates which served as antibody mimics for bacteria capturing. This LFIA has not only eliminated the intricate antibody labeling process and screening of paired antibodies in conventional LFIAs, but also promised dual-readout (colorimetric/Raman) for flexible detection. Under optimized conditions, this LFIA achieves selective detection of S. enteritidis with a low visual detection limit of 103 CFU/mL and a broad linear range of 103−108 CFU/mL. Additionally, the LFIA could be successfully applied in drinking water and milk with recoveries of 85%–109%. This work is desirable to expand the application of 2D TMDs in biosensors and offers a brand-new alternative protocol of detection antibodies in foodborne pathogens detection. [ABSTRACT FROM AUTHOR]

Salbutamol (SAL) residues in edible animal tissues have various adverse effects on human health after digestion. Herein, we constructed an innovative functionalized microorganism nanozyme-mediated immunochromatographic assay for sensitive and accurate dual-colorimetric detection of SAL by introducing the Yeast@IrO 2 as bifunctional signal tag. The Yeast@IrO 2 was synthesized by self-assembling iridium (IV) oxide nanoparticles (IrO 2 NPs) on the surface of inactivated yeast cells, which showed high monodispersity, uniform shapes, preeminent biocompatibility and rapid antibodies labeling capacity. After reaction for 15 min, through further employing [3,3′,5,5' Tetramethylbenzidine (TMB) and hydrogen peroxide (H 2 O 2)] as substrate to trigger the color reaction, the developed biosensor performed with outstanding performance, including limit of detection (0.012 ng/mL), linearity (R2 > 0.99) and selectivity. Concurrently, the visual limit of detection (0.2 μg/kg) and satisfactory recoveries (85.6%–103.9%) were obtained by monitoring SAL in pig liver and beef samples. Briefly, this work provided a universal platform for sensitive, precise and rapid detection of toxic and hazardous substances in food safety fields. • A microorganism nanozyme-mediated ICA was developed to detect salbutamol. • The Yeast@IrO 2 was designed by self-assembling IrO 2 NPs on inactivated yeast cells. • The Yeast@IrO 2 generated colorimetric- and catalytic-based dual signals. • The sensor showed lower detection limit (0.012 ng/mL) and broader detection range. • The sensor could be applied to the detection of SAL in beef and pig liver samples. [ABSTRACT FROM AUTHOR]

• The Sc nanocubes based immunoassay was developed for detection of imidacloprid. • The Sc nanocubes had large surface area, remarkable intensity and biocompatibility. • The sensor had a low limit of detection and specificity for imidacloprid detection. • Satisfactory analytical results in real samples suggested the sensor's applicability. In this work, a highly sensitive immunochromatographic test strip (ITS) based on Scandium-Tetrakis (4-carboxyphenyl) porphyrin (TCPP) metal–organic framework nanocubes (ScTMNs) was developed for ultrasensitive and facile visual determination of imidacloprid (IDP). TCPP as the porphyrin-based planar ligand and Sc3+ as the metal center were applied to form the ScTMNs via coordination chelation. Giving the credit to its excellent optical characteristics, strong affinity with monoclonal antibodies, and favorable biocompatibility, the ScTMNs was selected as a signal tag. Under optimized conditions, the ITS exhibited a great liner relationship in the range of 0.04–3 ng/mL and the detection limit was 0.04 ng/mL for the IDP detection. Additionally, IDP was successfully detected in tomatoes, millet, corn and carrot samples with satisfied recoveries. To the best of our knowledge, this is the first time that ScTMNs have been used in immunochromatography which are expected to have potential applications in detection of other substances. [ABSTRACT FROM AUTHOR]

A novel ratiometric fluorescence probe was designed for the determination of Al3+ by self-assembling of NH2-MIL-101(Fe) and [Ru(bpy)3]2+. Under the excitation wavelength of 360 nm, the NH2-MIL-101(Fe)@[Ru(bpy)3]2+ presented a dual-emitting luminescent property at 440 and 605 nm, respectively. In the presence of Al3+, the blue fluorescence of NH2-MIL-101(Fe)@[Ru(bpy)3]2+ at 440 nm was enhanced remarkably, while the red emission at 605 nm was almost not influenced. Therefore, taking the fluorescence at 440 nm as the report signal and 605 nm as the reference signal, quantitative determination was achieved for Al3+ concentration in the ranges 0.2–25 μM and 25–250 μM. The limit of detection (LOD) and limit of quantification (LOQ) were calculated to be 73 nM and 244 nM, respectively. The sensing mechanisms were studied by theoretical calculation and optical spectra. The analysis of real food samples confirmed the suitability of the proposed method. More importantly, portable fluorescent test papers were successfully manufactured to provide a strategy for visual, rapid, and on-site detection of Al3+. [ABSTRACT FROM AUTHOR]

To overcome limitations with respect to the low sensitivity of rapid immunoassay methods due to dilution of the extract in extraction solution, ultra-sensitive antibodies are needed. The linker-tethering site between the target and carrier protein, the length of the spacer arm, and the atomic charge of the linker-tethering site between the target and spacer arm in haptens design play a pivotal role in the preparation of ultra-sensitive antibodies. In this study, carbendazim (CBZ), a systemic broad-spectrum fungicidal pesticide, was used as model compound. 2-Aminobenzimidazole was chosen as the common skeletal structure and reacted with different groups, such as alkanes and urine groups, to form haptens H1 (previously reported), H2 (novel), and H3 (novel), respectively. Subsequently, eight monoclonal antibodies (mAbs) were generated using these three haptens, which exhibited notable variation in sensitivity. The half maximal inhibitory concentration (IC 50) value of mAb 4B11 based on hapten H3 against CBZ was 0.04 ng/mL, which was seven times better than that of mAb 5B10 (IC 50 value of 0.28 ng/mL) prepared using hapten H2 and 129 times better than that of mAb 6D5 (IC 50 value of 5.15 ng/mL) prepared using hapten H1. Finally, the optimal antigen–antibody combination was employed to establish a sensitive colloidal gold lateral flow immunoassay (CG-LFA) for CBZ detection in vegetables and fruits with convenient sample pretreatment. The developed CG-LFA shows promising practical utility and prospects for application due to its low limit of detection (0.10–0.18 ng/mL) and high recovery ratios (76.0%–96.1%) in six different samples. [Display omitted] • A novel hapten design strategy focuses on the link site and spacer arm length of the target compound. • An ultra-sensitive monoclonal antibody (mAb) 4B11 against carbendazim was prepared. • A sensitive colloidal gold lateral flow immunoassay in fruits and vegetables was developed. [ABSTRACT FROM AUTHOR]

In the past few years, ambipolar tin monoxide (SnO) thin-film transistors (TFTs) have been widely studied because of ever-increasing demands for simplifying CMOS circuit and fabrication of more compact CMOS devices. However, in view of the serious decline in device performance upon gate-bias stress and environmental exposure, it is urgent to develop an effective passivation strategy for improving the operational stability of SnO TFTs. Here, aluminum oxide (Al2O3)/hafnium oxide (HfO2) bilayer dielectric is employed as a passivation layer for achieving ambipolar SnO TFTs with greatly enhanced operational stability, in which the Al2O3 dielectric is used to reduce the interfacial trap states, while HfO2 dielectric can prevent the diffusion of water/oxygen. Furthermore, a complementary-like inverter is presented by simply connecting two identical ambipolar SnO TFTs, which can be maintained in ambient condition for more than four months with a voltage gain exceeding 30. The capacity to synchronously achieve field-effect conversion, operational stability, as well as logic function in ambipolar SnO TFTs opens up a rational avenue to the realization of compact logic circuits. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) with its outstanding performance in ultra-sensitivity has been applied in contaminants monitoring. Herein, a facile strategy of integrating oriented layered MOF nanoarray with controlled electrodeposition of gold nanoparticles via semi-sacrificial template method was proposed to fabricate a versatile self-supporting MOF chip (S-MOF@Au) for efficient SERS detection of food contaminants. The S-MOF was ingeniously formed by directly using flexible Ni sheet as both metal source and scaffold, which in favour of greatly improving intrinsic electrical conductivity during electrodeposition process as well as endowing prepared chip with uniform distribution of gold nanoparticles and high stability. Furthermore, amounts of SERS "hot spots" in the oriented layered S-MOF@Au can yield strong electromagnetic field for Raman amplification with superior reproducibility. By virtue of good flexibility and pre-concentration effect of S-MOF@Au, tartrazine (TA), chloramphenicol (CP), imidacloprid (IDP) and crystal violet (CV) in food samples were sensitively detected using three collected approaches (drip coating, soaking and wiping) with low limits of detection (1.0 × 10−9 M for TA, 8.0 × 10−11 M for CP, 6.4 × 10−11 M for IDP and 5.0 × 10−12 M for CV), wide linear detection ranges (1.0 × 10−8 – 1.0 × 10−3 M for TA, 1.0 × 10−10 – 1.0 × 10−6 M for CP, 1.0 × 10−10 – 1.0 × 10−7 M for IDP and 1.0 × 10−11 – 1.0 × 10−7 M for CV) and satisfactory recoveries (96.2 – 125.1%). This method provides a novel strategy to develop an advanced SERS platform for efficient food contaminants monitoring. [Display omitted] • A versatile self-supporting SERS chip (S-MOF@Au) was ingeniously constructed. • S-MOF possesses good electrical conductivity with uniform distribution of Au NPs. • S-MOF@Au can improve Raman amplification with superior reproducibility. • Drip coating, soaking and wiping for contaminants can be realized using S-MOF@Au. • Four typical food contaminants were sensitively detected based on S-MOF@Au. [ABSTRACT FROM AUTHOR]

With the increasingly serious problem of antimicrobial resistance and the lack of clinical response strategies, the development of new antibacterial materials is imminent. Herein, a VIS/NIR co-irradiation photodynamic-photothermal and oxidase-like synergistic antibacterial platform of transition metal sulfide/TiO 2 nanofibers (TMSs/TiO 2 NFs) is proposed to fight bacterial infection. On one hand, three-dimensional (3D) MoS 2 nanoflowers load can quickly capture the photogenerated electrons of two-dimensional (2D) TiO 2 nanofibers, inhibit the recombination of electron-hole pairs and greatly increase the yield of reactive oxygen species (ROS), thereby overcoming the UV sterilization defects of pure TiO 2 , endowing TiO 2 excellent photodynamic antibacterial ability in the long-wavelength region. On other hand, with the combination of MoS 2 and TiO 2 , the photothermal effect of the 3D/2D heterostructure (MoS 2 /TiO 2 NFs) was significantly enhanced and the local temperature rose to above 50 °C in a short time, which was enough to induce the inactivation of bacterial protein, thereby providing an efficient secondary sterilization effect. In addition, MoS 2 /TiO 2 NFs has fascinating oxidase-like activity, which further accelerated the oxidation of physiologically relevant antioxidants in bacteria. In the end, MoS 2 /TiO 2 NFs exerted outstanding antibacterial efficiencies against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through the synergy of photodynamic-photothermal and oxidase-like performance. Meanwhile, MoS 2 /TiO 2 NFs antibacterial platform effectively accelerated the healing of S. aureus -infected wounds and showed negligible toxicity and hemolysis on normal cells and tissues. Hence, this study contributed an effective alternative strategy for reducing the use of antibiotics, providing new ideas for application of semiconductor nanomaterials in collaborative combination therapy. [Display omitted] • The 3D/2D TMSs/TiO 2 NFs (MoS 2 /TiO 2 NFs) heterojunctions are successfully prepared in situ. • MoS 2 /TiO 2 NFs heterojunctions are demonstrated to increases the yield of ROS. • MoS 2 /TiO 2 NFs show enhanced photodynamic-photothermal and oxidase-like properties. • MoS 2 /TiO 2 NFs process charming sterilization activity. • MoS 2 /TiO 2 NFs antibacterial agent accelerate S. aureus- infected wound healing. [ABSTRACT FROM AUTHOR]

Based on DFT-B3LYP/6-311G** method, the molecular geometric structures of polynitramineprismanes are fully optimized. The detonation performances, energy gaps, strain energies, as well as their stability were investigated to look for high energy density compounds (HEDCs). Our results show that all polynitramineprismanes have high and positive heat of formation. To construct the relationship between stabilities and structures, energy gaps and bond dissociation energies are calculated, and these results show that the energy gaps of prismane derivatives are much higher than that of TATB (0.1630). In addition, the C-C bonds on cage are confirmed as trigger bond in explosive reaction. All polynitramineprismanes have large strain energies, and the strain energies of all compounds are slightly smaller than prismane, which indicated that the strain energies were somewhat released compared to prismane. Considering the quantitative criteria of HEDCs, hexanitramineprismane is a good candidate of high energy compounds. [ABSTRACT FROM AUTHOR]

Based on fully optimized geometric structures at DFT-B3LYP/6-311G** level, we calculated electronic structures, heats of formation, strain energies, bond dissociation energies and detonation performance (detonation velocity and detonation pressure) for a series of polynitraminecubanes. Our results have shown that energy gaps of cubane derivatives are much higher than that of triaminotrinitrobenzene (TATB), which means that cubane derivatives may be more sensitive than TATB. Polynitraminecubanes have high and positive heats of formation, and a good linear relationship between heats of formation and nitramine group numbers was presented. As the number of nitramine groups in the molecule increases, the enthalpies of combustion values are increasingly negative, but the specific enthalpy of combustion values decreases. It is found that all cubane derivatives have high strain energies, which are affected by the number and position of nitramine group. The calculated bond dissociation energies of C-NHNO and C-C bond show that the C-C bond should be the trigger bond in the pyrolysis process. It is found that detonation velocity ( D), detonation pressure ( P) and molecule density ( ρ) have good linear relationship with substituented group numbers. Heptanitraminecubane and octanitraminecubane have good detonation performance over 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), and they can be regarded as potential candidates of high energy density compounds (HEDCs). The results have not only shown that these compounds may be used as HEDCs, but also provide some useful information for further investigation. [ABSTRACT FROM AUTHOR]

In recent years, nanozyme-photothermal therapy (NPT) has attracted enormous interests owing to their enhanced therapeutic effects and less adverse effects in the treatment of infectious diseases. However, the development of nanozyme-photothermal agents (NPAs) that can rapidly, efficiently and synergistically combating pathogenic bacteria remains a huge challenge due to the limitation of size effect. Herein, by decorating platinum nanozymes on Zn-based photosensitizer, we report a novel metal-organic framework (MOF)-derived hybrid nanozymes antibacterial strategy for enhanced NPT. This strategy can not only prevent the aggregation of platinum nanozymes and effectively reduce the mass transfer resistance during the kinetic reaction, but also inhibit the photoelectron-hole recombination in the process of photothermal therapy (PTT) and improve the photothermal conversion performance. In the presence of a low concentration of hydrogen peroxide (H 2 O 2), the superior nanocatalytic activity of the MOF-derived hybrid nanozymes can effectively catalyze the release of H 2 O 2 to generate toxic hydroxyl radical (•OH), resulting in the increase of bacterial membrane permeability and thermal sensitivity. Once the near-infrared laser is introduced, the nanozyme-photothermal antibacterial platform can play the role of "nanoknife" to further induce the death of the damaged bacteria by physical cutting. In vitro and vivo in antibacterial assays confirm that the MOF-derived hybrid nanozymes have excellent antibacterial properties, which can serve as an antibacterial candidate with negligible adverse effect. Therefore, this work will open a new avenue for MOF-derived hybrid nanozymes in biomedical application. [Display omitted] • The MOF-derived hybrid nanozymes antibacterial strategy was used to enhance the nanozyme-photothermal therapy. • The PEG@Zn/Pt–CN nanozyme-photothermal antibacterial platform processed excellent ROS-released and NIR-responsive property. • The PEG@Zn/Pt–CN nanozyme-photothermal antibacterial platform could kill 98.74% E. coli and 99.63% S. aureus. • Wound infection model experiments confirmed the antibacterial activity and the rapid tissue repair effect. [ABSTRACT FROM AUTHOR]

The valorization, resource generation and the functional characteristic exploration of domestic waste still face enormous challenges. Kiwi peels, a common kind of fruit waste, contain a large amount of phenolic substances, including polyphenols, flavonoids, etc., which can be explored and reused in food and biomedical fields. By ultrasonic assisted extraction technology, we obtained conversional fluorescence kiwi peel phenolic extracts (PE) which possessed gradient magenta fluorescence relying on the content of ethanol in the solution, as well as strong antioxidant activity. Besides, metal ions sensing assay revealed that PE can specifically sense Hg2+ and Cu2+ (LOD: 1.16 and 0.17 μM, respectively) accompanied with a fluorescence conversion from magenta fluorescence to blue. Moreover, employing the prepared PE as fluorescent probes, imaging of HeLa cells can be easily achieved with satisfactory resolution. Additionally, PE was incorporated into the gelatin matrix, successfully fabricating a green, edible degradable film with excellent antioxidant activity. Unlabelled Image • Ultrasound treatment accelerated the escape of kiwi peel phenolic extracts. • Phenolic extracts exhibited a gradient magenta fluorescence relying on the solvent effects. • Phenolic extracts sense Hg2+ and Cu2+ with a fluorescence conversion from magenta to blue. • Phenolic extracts were successfully applied to fluorescent imaging of HeLa cells. • Phenolic extracts improved the antioxidant capacity of gelatin-based films. [ABSTRACT FROM AUTHOR]

Developing a facile method to fabricate new heterogeneous Metal-Organic Framework (MOFs) based catalysts with high catalytic activity and stability has drawn significant attention. Herein, we demonstrate a simple in-situ pyrolysis reduction strategy to fabricate a novel three-dimensional (3D) Cu-based catalyst, which displays an outstanding performance for the decomposition of 4-nitrophenol (4-NP). Detailed characterization including SEM, FTIR, XPS, ICP-OES, HRTEM, SAED, XRD and BET confirmed the formation of the Cu/C porous composites (Cu/C-PC). Taking advantage of enormous Cu particles in the composite as well as ultrahigh surface area (196.7 m2/g) of carbon support, Cu/C-PC presents prominent catalytic activity for the hydrogenation reduction 4-NP to 4-aminophenol (4-AP) with apparent rate constant (K app) of 0.0267 s−1 (the ratio of K app to the catalyst amount is 119 s−1 g−1), which is dramatically higher than that previous reports. On the contrary, after being washed successively (Cu/C-PC-AW) by FeCl 3 , HCl aqueous solution and deionized water, the Cu/C porous composite materials exhibit fairly weak catalytic activity. The catalytic performance of Cu/C-PC is better than Cu, Cu 2 O and CuO nanoparticles as well as other catalysts in previous reports. Furthermore, Cu/C-PC shows excellent reusability, indicating its potential applications in treatment of water pollution. [ABSTRACT FROM AUTHOR]

[Display omitted] • N/Co@CNTs@CC was prepared by sublimation-gas phase transition strategy. • N/Co@CNTs@CC exhibits uniform N doping, hollow structure and active metal sites. • The growth mechanism of N -doped carbon nanotubes was investigated. • N/Co@CNTs@CC has excellent feasibility in food samples. Designing efficient and sensitive methods for the detection of nitrofurantoin (NFT) residues is of great importance for food safety and environmental protection. Herein, a composite with cobalt nanoparticles encapsulated in nitrogen-doped carbon nanotube (N/Co@CNTs@CC-II) was synthesized by in-situ growth and sublimation-gas phase transformation strategy and used to establish an ultrasensitive electrochemical sensor for NFT determination. The N/Co@CNTs@CC-II sensor exhibits uniform N doping, fine hollow structure, and abundant active metal sites, which lays a solid foundation for the ultra-sensitive detection of NFT. Benefiting from these advantages, the N/Co@CNTs@CC-II exhibits excellent sensitivity (8.19 μA μM−1 cm−2) and low detection limit (18.41 nM) for NFT detection. The practical feasibility of N/Co@CNTs@CC-II was also demonstrated by the determination of NFT in milk and tap water samples. This study may open up new opportunities for the application of N -doped carbon nanotube materials encapsulating transition metals. [ABSTRACT FROM AUTHOR]

[Display omitted] • The hierarchical SnO 2 /CC was designed and synthesized for IDP detection. • The in situ derivatization strategy was proposed in this paper. • SnO 2 /CC created the structural advantage to improve catalytic activity. • SnO 2 /CC exhibits favorable electrocatalytic reduction performance for IDP. Designing sensitive and rapid sensing platforms for detection of pesticide residues is essential for food safety. Herein, we designed and synthesized the hierarchical SnO 2 nanoparticles on carbon cloth (SnO 2 /CC) for the electrochemical detection of imidacloprid (IDP) based on in situ derivatization strategy. The hierarchical structure of SnO 2 /CC can maintain the original nanosheet morphology of SnS 2 and prevent the aggregation of SnO 2 nanoparticles, which endows SnO 2 /CC with a large specific surface area, abundant active sites, and fast electron transfer, which is beneficial to improve its electrocatalytic performance. Electrochemical studies showed that SnO 2 /CC exhibited favorable sensing performance for IDP under optimized conditions, including a linear range of 0.5–60 μM, extremely high sensitivity of 60.88 μA μM−1 cm−2, and a low detection limit of 0.056 μM. Additionally, the electrode was verified to have satisfactory feasibility by detecting IDP in grape and apple samples. This work opens a new perspective for the fabrication of high-performance IDP electrochemical sensors based on hierarchical nanostructured metal oxide. [ABSTRACT FROM AUTHOR]

Developing electrode materials with excellent electrocatalytic properties for detecting pesticide residues plays a vital role in the safety of agricultural products and environmental applications. Herein, we designed a new electrochemical sensor on the basis of N-doped carbon hollow nanospheres modified with Sn/MoC Schottky junction (Sn/MoC@NC) for methyl parathion (MP) detection. The Sn/MoC@NC was prepared by self-assembled polymerization-anchoring strategy and high-temperature carbonization design. Sn/MoC Schottky junction and hollow nanosphere structure endow Sn/MoC@NC with a larger surface area, more active sites, and faster electron transfer, which is beneficial to enhancing its electrocatalytic performance. The structural characterizations and physicochemical properties of Sn/MoC@NC were explored through various microscopy, spectroscopic and electrochemical techniques. The experimental results confirmed that the calibration curve for current and MP concentration (0.05–10 μg/mL) was available under optimized conditions, and the sensitivity and detection limit were respectively determined to be 9.02 μA μM 1 cm 2 and 8.9 ng/mL. Furthermore, the constructed sensor displayed excellent selectivity, repeatability, and stability, which qualified it for use in detecting MP in grapes and tap water with satisfactory recovery. This work may provide some interesting prospects for constructing high-performance electrocatalysts for MP detection. [Display omitted] • Sn/MoC@NC Schottky catalyst was designed and synthesized for MP detection. • The self-assembled polymerization-anchoring strategy was proposed in this paper. • The coupling of of Schottky junction and nano hollow improve catalytic activity. • Sn/MoC@NC/GCE exhibits superior electrocatalytic reduction performance for MP. [ABSTRACT FROM AUTHOR]

It is an important task to real-time monitor biogenic amines (BAs) released from perishable seafood for predicting their freshness. To this endeavor, herein we developed a simple and effective strategy for visual determination of BAs by dual-emissive metal-organic framework (MOF) probes and color-transition hydrogels. Through situ encapsulating Ru(bpy) 3 2+ into UiO-OH, the functionalized Ru@UiO-OH was solvothermally prepared. At a single excitation wavelength, the fluorescence intensity of Ru@UiO-OH at 537 and 600 nm showed different changes in the case of trimethylamine (TMA), leading to a ratiometric platform with apparent color variation from orange red to bright yellow. The achieved turn-on yellow emission resulted from the inhibition of LMCT and ESIPT process caused by MOF skeleton damage and deprotonation. Intelligently, Ru@UiO-OH was loaded into hydrogels that acted as "sniffing" trademarks to detect volatile TMA vapor, which was further integrated with a smartphone-based readout to quantify. Meanwhile, the practical applicability of fluorescent sensory hydrogels was confirmed via depicting the spoilage degree of shrimp and fish at 4 and 20 ℃, the results were good consistent with standard method for detection of total volatile basic nitrogen (TVB-N). The current creation holds great significance for precise guidance of sensing seafood freshness with straightforward manner. [Display omitted] • Dual-emitting Ru@UiO-OH has been solvothermally prepared by situ encapsulation. • The red-emission acted as a reference, overcoming the interference of environment. • Hydrogel-based "sniffing" sensing platform with color transition was constructed. • The hydrogel label successfully described the spoilage degree of shrimp and fish. [ABSTRACT FROM AUTHOR]

Apart from the obvious benefit of "trash-to-treasure", the acquisition of natural nanomaterials from cheap and renewable waste has been intensively researched because of various bioactivities and physical-chemical features. Herein, for the first time, we employed natural cuttlefish ink nanoparticles (CINPs) as a multifunctional label and designed colorimetric-photothermal dual-mode lateral flow immunoassays (CINPs-mediated CPLFIA) for sensitive detection of clenbuterol (CL). The accessibility and renewability of CINPs overcome barriers that artificial nanomaterials face, such as complex manufacturing and relatively high costs. Additionally, inspired by the mussel adhesion, the bio-affinity of CINPs, such as antibody coupling and preservation, was investigated and showed to be considerably superior to Au NPs, leading to significantly increased immunosensor sensitivity. Meanwhile, CINPs exhibit excellent photothermal conversion efficiency for dual-signal production, avoiding the effect of environmental elements (particularly light) for colorimetric mode. Besides, the biosensor was integrated with a smartphone and a thermal imager for portable sensing. After optimization, the detection limit of CINPs-mediated CPLFIA was 0.179 ng mL−1 (colorimetric mode) and 0.076 ng mL−1 (photothermal mode), which were significantly lower than traditional gold nanoparticles-based LFIA (0.786 ng mL−1). This research attempted to explain the rise in sensitivity. From food waste to food supervision, this research explores the hidden value of natural resources. • Cuttlefish ink nanoparticles (CINPs) were first used in lateral flow immunoassay (LFIA). • It conformed to the "trash-to-treasure" and circular economy principles. • It contrasted how well antibodies coupled to CINPs and Au NPs. • It assessed the CINPs' photothermal conversion efficiency. • It designed colorimetric-photothermal dual-mode LFIA with portable devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple MICP was developed for simultaneous detection of antibiotics. • The ICA was decorated with crystal violet (CV) to offer improved properties. • A synthesis-free CV tag was employed to label different antibodies. • Successful applications in food samples demonstrated the feasibility of MICP. Antibiotic abuse has caused serious health risks for human beings for long. To address the problem, novel and facile detection techniques are highly desired. Here, an effective multiplex immunochromatographic platform (MICP) with synthesis-free and cost-effective merits is established for simultaneous detection of antibiotics on a single immunochromatographic assay (ICA) strip. Adopting crystal violet (CV) as a signal tag for multiplex ICA allows for direct coupling with multiple antibodies in several minutes. By combining CV and ICA perfectly, this convenient strategy offers improvements in convenience, speed, flexibility, and portability, eventually ensuring the optimized effectiveness of this approach. As a result, the established platform is successfully used to detect streptomycin (STR) and chloramphenicol (CAP) with visual detection mode, and the obtained total recoveries of milk and honey real samples changed from 83.82 to 113.38% with total RSD values of 0.48 to 4.15%. [ABSTRACT FROM AUTHOR]

Excessive residues of nitrofurantoin (NFT) can cause serious contamination of water bodies and food, and potential harm to ecosystems and food safety. Given that, rapid and efficient detection of NFT in real samples is of particular importance. MoS 2 is a promising electrochemical material for this application. Here, MoS 2 was modulated by Metal-organic framework through the interfacial microenvironment to enhance the catalytic activity and carbonized to form Co 2 Mo 3 O 8 nanosheets with high electrical activity. The resulting Co 2 Mo 3 O 8 /MoS 2 hybrid structure can be used to prepare highly sensitive NFT electrochemical sensor. The Co 2 Mo 3 O 8 /MoS 2 @CC electrochemical sensor exhibits strong electrochemical properties due to its fast electron transfer, excellent electrical conductivity, abundant defect sites, and high redox response. Based on this, this electrochemical sensor exhibited excellent electrocatalytic activity for NFT with a wide linear detection range, low detection limit, and high sensitivity. Moreover, the electrode was successfully applied to detect NFT in milk, honey, and tap water, strongly confirming its potential in real samples. This work could furnish the evidence for interfacial microenvironmental regulation of MoS 2 , and also offer a novel candidate material for NFT sensing. [Display omitted] • The sensor with rich Co2Mo3O8/MoS2 hybrid structure were fabricated. • Highly electroactive Co2Mo3O8 nanosheets are formed by carbonization reduction. • Interfacial microenvironment modulation can improve the catalytic activity of MoS2. • Efficient electrocatalytic reduction of NFT is achieved on Co2Mo3O8/MoS2@CC sensor. [ABSTRACT FROM AUTHOR]

Nature-derived bioactive components and photothermal synergistic therapy bring potential strategies for fighting bacterial infection and accelerating would healing by virtue of their excellent therapeutic efficiencies and ignorable side effects, where photothermal property not only acts as sterilization energy but also as a doorkeeper to control the natural component release. Herein, by integrating the excellent antibacterial property of cinnamaldehyde (CA) and the outstanding photothermal performance of copper sulfide nanoparticles (CuS NPs), a multifunctional nanoplatform of SiO 2 @CA@CuS nanospheres (NSs) is constructed with silica nanosphere (SiO 2 NSs) as carrier. SiO 2 @CA@CuS NSs exhibit photothermal property, bacterial absorption capacity, extraordinary antibacterial activity and antioxidant property. Mechanism characteriazation and antibacterial experiment indicate that positive charged SiO 2 @CA@CuS can adhere to the negative charged surface of bacteria, and quickly kill bacteria through the synergistic action of the released CA and heat produced under near infrared light (NIR) irradiation at 980 nm. The sterilization efficiencies for Escherichia coli (E. coli) and S. aureus reach 99.86% and 99.84%, respectively. Furthermore, NIR-regulated SiO 2 @CA@CuS perform great biocompatibility, as well as effective effects for accelerating S. aureus -infected wound healing at a low photothermal temperature (45 °C) relying on synergistic sterilization and anti-oxidation. [Display omitted] • Mesoporous silica loaded with CA performs electropositive. • Photothermal energy: antibacterial energy and a doorkeeper of cinnamaldehyde. • NIR-induced cinnamaldehyde release and photothermal synergistic therapy. • Promoting blood vessel growth and accelerating infected-wound healing. [ABSTRACT FROM AUTHOR]

• A ratiometric strategy combined fluorescence and scattering signals was developed. • Two signal collection tactics based on fluorescence and scattering were proposed. • The sensor can be stimulated by one excitation and measured on single instrument. • The sensor was applied in real samples for Hg2+ detection with favorable results. A new ratiometric platform was developed for sensing Hg2+, which combined fluorescence and scattering simultaneously. This ratiometric strategy reflected superiorities over conventional methods, since the two independent signals at irrelevant categories meet the requirements of sufficient wavelength separation, stimulation under one excitation, and collection on single instrument. Herein, nonconjugated polymer dots (N -PDs) were served as the recognition unit for Hg2+ with turn-off fluorescence and turn-on scattering. Additionally, two signal collection tactics were proposed to achieve fluorescence and scattering in a window: one was to record down-conversion fluorescence and second-order scattering spectra (FL@SOS), and the other was to gather the fluorescence excited by second-order diffraction light and first-order scattering (SODL-FL@FOS). This ratiometric sensor exhibited outstanding performance toward Hg2+ in the range of 0.1–50 μM with the detection limit of 27 nM. By contrast, the present proposal provided a more ingenious and scalable way to construct ratiometric sensor than traditional approach. [ABSTRACT FROM AUTHOR]

As part of a search for high energy density materials (HEDMs), a series of purine derivatives with nitro groups were designed computationally. The relationship between the structures and the performances of these polynitropurines was studied. Density functional theory (DFT) at the B3LYP/6-311G** level was employed to evaluate the heats of formation (HOFs) of the polynitropurines by designing an isodesmic reaction method. Results indicated that the HOFs were influenced by the number and positions of substituent groups. Detonation properties were evaluated using the Kamlet-Jacobs equations, based on the theoretical densities and heats of formation of the polynitropurines. The relative stabilities of the polynitropurines were studied via the pyrolysis mechanism and the UB3LYP/6-311G** method. Homolysis of the ring-NO bond is predicted to be the initial step in the thermal decomposition of these purine derivatives. Considering their detonation properties and relative stabilities, the tetranitropurine (D1) derivatives may be regarded as potential candidates for practical HEDCs. These results may provide useful information for further investigations. [ABSTRACT FROM AUTHOR]

• The MoO 3 /Co 3 O 4 heterostructure was formed via a hybrid electrochemical deposition strategy. • The synergistic effect of Co 3 O 4 and MoO 3 plays a predominant role in nitrite electrooxidation. • The MoO 3 /Co 3 O 4 /CC has been successfully used in food samples for nitrite detection. Considering excess nitrites are detrimental to the human body and environment, designing a rapid, sensitive, and real-time quantitative determination for nitrite is of great significance for environmental preservation and public health. In this paper, Co 3 O 4 nanoflowers coupled with ultrafine MoO 3 nanoparticles (MoO 3 /Co 3 O 4) are obtained via a hybrid electrochemical deposition strategy (HED). The as-designed MoO 3 /Co 3 O 4 /CC integrating electrode exhibits superior electrocatalytic properties towards nitrite oxidation, owing to the synergistic effect between MoO 3 and Co 3 O 4 caused by the heterostructure of MoO 3 /Co 3 O 4. The electrode achieved a low response time of 2 s, an excellent sensitivity of 1704.1 μA mM−1 cm−2, and a low limit of detection of 0.075 μM (S/N = 3). Furthermore, the electrode displays promise for nitrite detection in complex food such as water and sausages samples. Our study will provide a significant strategy for the application of bimetallic heterostructure to explore the design of sensing interfaces. [ABSTRACT FROM AUTHOR]

[Display omitted] • The novel Ru@V 2 O 4 nanocomposite were synthesized successfully by facile hydrothermal approach. • With the introduction of Ru, the Ru@V 2 O 4 nanocomposite exhibited enhanced catalytic performance. • The synthesized Ru@V 2 O 4 nanowires possessed superior tetra-enzyme-like activities. • A very low limit of detection of 0.788/0.139 μM was obtained for H 2 O 2 /Cys detection, respectively. • This prominent technique could be applied in water samples and human serum samples. In the last decades, nanozymes have drawn significant attention because of their higher stability and lower preparation cost than natural enzymes. In this report, the novel Ru@V 2 O 4 nanocomposite with multi-enzyme-like activities has been synthesized via one-step hydrothermal method and simple stirring. It was proved that the prepared Ru@V 2 O 4 nanowires presented magnificent tetra-enzyme-like activities, comprising oxidase-like (OD-like), peroxidase-like (POD-like), catalase-like (CAT-like) and superoxide dismutase-like (SOD-like) activity. Firstly, the kinetic investigation validated the OD and POD-mimics behaviors of Ru@V 2 O 4 nanowires, which were in conformity with the Michaelis-Menten kinetics. Then a bifunctional colorimetric sensing platform was constructed for the sensitive detection of H 2 O 2 and cysteine (Cys) on the basis of POD-like and OD-like enzyme activities of Ru@V 2 O 4 nanowires. H 2 O 2 could be detected by Ru@V 2 O 4 nanowires over a range of 1–500 μM and the response limit was 0.788 μM. Under optimal conditions, the degree of discoloration was linearly proportional to the concentration of Cys in the range of 3–50 μM with a low detect limit of 0.139 μM. Besides, Ru@V 2 O 4 nanowires can detect H 2 O 2 in water samples and Cys in serum samples. Therefore, this research significantly expands the application of the tetra-enzyme mimetic Ru@V 2 O 4 nanowires in the fields of biosensing, biocatalysis, environmental monitoring and medical diagnosis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magnetic Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs were successfully fabricated. • Fe, Ti and Zr in MOF were investigated to reveal the influence on azo dye adsorption. • The Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs were used for adsorption of azo dyes in soft drinks with high capacities. • Adsorption mechanisms were systematically explored. Azo dyes in soft drinks present a serious risk to human health and are strictly limited in many countries. Herein, we demonstrate that covalent-organic framework (COF) can be facilely grown on magnetic metal–organic framework (MOF) to form three kinds of porous Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs composites for efficient azo dyes adsorption. Adsorption performances of Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs toward azo dyes were systemically investigated by adsorption kinetics, adsorption isotherms and adsorption thermodynamics. Under optimized conditions, the maximum adsorption capacities of both Fe 3 O 4 @MOF(Fe)@COF and Fe 3 O 4 @MOF(Zr)@COF for Congo red (CR) are 1250.02 and 625.13 mg g−1, and the Fe 3 O 4 @MOF(Ti)@COF for Chrysoidine (CYD) is 294.12 mg g−1, all which are higher than those of mostly previous reports. Furthermore, possible mechanisms of adsorption were revealed through Fourier-transform infrared spectra and X-ray photoelectron spectroscopy analysis. These Fe 3 O 4 @MOF(M = Fe, Ti, Zr)@COFs composites also present good biocompatibility, and exhibit high adsorption capacities for CR or CYD in soft drinks, which can be suggested as effective adsorbents for the azo dyes removal from soft drinks. [ABSTRACT FROM AUTHOR]

Electrochemical analysis enables pesticides monitoring become rapid and efficient. Herein, novel three dimensional nitrogen–doped macro–meso–microporous carbon composites (N/Cu–HPC) derived from polyvinylpyrrolidone (PVP) doped Cu–metal organic framework were successfully formed via one–pot solvothermal method followed by pyrolysis, which were further applied in high–performance electrochemical determination of neonicotinoid. The introduction of PVP endows the N/Cu–HPC good hydrophilicity preventing aggregation as well as more highly electronegative nitrogen species boosting electro–catalytic property dramatically. Interestingly, the macro–meso–microporous architecture improves mass and charge transports between neonicotinoid molecules and active sites such as Cu nanoparticles and carbon atoms possessing Lewis basicity next to pyridinic-N. Based on the N/Cu–HPC, imidacloprid (IDP), thiamethoxam (THA) and dinotefuran (DNF) were detected with wide linear detection ranges (0.5–60 μM for both IDP and DNF, 1–60 μM for THA) and low detection limits (0.026 μM for IDP, 0.062 μM for THA and 0.01 μM for DNF). Meanwhile, this sensor can be successfully used for determination of IDP, THA and DNF in oat, corn and rice with good recoveries (92.0–100.9%, RSD ≤ 4.8%), demonstrating that the N/Cu–HPC possesses a high potential to be an advanced sensing device for monitoring neonicotinoid in agricultural products. [Display omitted] • 3D hierarchical porous N/Cu-HPC was successfully constructed via PVP-assisted strategy followed by pyrolysis. • Hydrophilicity and N species of N/Cu-HPC prevent aggregation as well as boost electro-catalysis performance. • The macro–meso–microporous architecture dramatically enhances mass diffusion of target molecules. • Imidacloprid, thiamethoxam and dinotefuran were sensitively detected using N/Cu-HPC. • The electrochemical reaction mechanisms toward neonicotinoid were systematically revealed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel europium-based MOF (1) was designed and synthesized. • 1 was applied in simultaneous detection and removal of tetracycline (TC). • 1 possesses ultrasensitive recognition and high adsorption capacity toward TC. • Mechanisms of recognition and adsorption were systematically explored. • 1 was used for TC detection in real samples with satisfactory recoveries. The misuse of tetracycline (TC) will cause adverse effects on environment and has become a serious problem threatening human health. In this work, a novel bifunctional europium-based metal organic framework (1) containing characteristic metal chains was successfully synthesized via a facile one-pot hydrothermal method for the first time and used in simultaneous detection and removal of TC. Detailed characterizations including scanning electron microscope, energy dispersive X-ray spectroscope, Fourier-transform infrared, X-ray diffraction and X-ray single crystal diffraction were conducted to confirm the successful synthesis of 1. Subsequently, the prepared 1 showed significant fluorescence enhancement at 615 nm with a wide sensitive range (0.05–60 μM) and low detection limit (3 nM) for detection of TC under pH 9. The excellent adsorption behaviours (387.14 mg g−1) of 1 toward TC were demonstrated by kinetic and equilibrium experiments. Possible mechanisms of recognition and adsorption including host-guest capability of Eu nodes, hydrogen bonding, π-π interactions and electrostatic attraction were further explored. In addition, the practical feasibilities of 1 for TC sensing were further investigated in real samples with satisfactory recoveries (94.89 %−112.86 %, RSD ≤ 6.03 %). This work provides a facile strategy for design of MOF-based bifunctional turn-on fluorescence sensor for efficient TC monitoring. [ABSTRACT FROM AUTHOR]

This study presented a facile approach for fabricating oil-in-water lavender essential oil nano-emulsions (LEONs) with excellent antibacterial and antioxidant activities. Besides, LEONs with different LEO content (50, 100, 200 and 300 μL/10 mL) were incorporated to the matrix of gelatin (GL) for preparing multifunctional GL-LEONs films, which exhibited strong antibacterial properties against Staphylococcus aureus , Escherichia coli and Listeria monocytogenes , as well as excellent antioxidant activities. Additionally, the GL-LEONs films exhibited sustained release characteristics, excellent UV light barrier performances and good heat-sealing properties. Furthermore, the GL-LEONs films were applied to the preservation of cherry tomatoes at 25 ± 2 °C for 7 days. The results revealed that the deterioration of cherry tomatoes packaged with the GL-LEONs films was suppressed during storage, which mainly reflected in reducing weight loss, delaying the degradation of titratable acids and phenolic components, and inhibiting the growth of microorganisms. • Oil-in-water lavender essential oil nano-emulsions (LEONs) were fabricated. • LEONs improved gelatin films antibacterial and antioxidant activities. • Gelatin-LEONs films exhibited sustained release and good heat-sealing properties. • Gelatin-LEONs films effectively maintained the freshness of cherry tomatoes. [ABSTRACT FROM AUTHOR]

• A self-cleaning SERS substrate was facilely formed through in-situ growth of leaf-like metal-organic framework and one-step electro-deposition of flower-like Ag nanoparticles (CC-L-MOF@F-Ag) followed by chemical modification. • This self-cleaning CC-L-MOF@F-Ag possesses competitive reproducibility with a lower RSD of 9.5%, good reusability after six cycles of sensing and excellent long-term stability for at least forty days. • The SERS detection using self-cleaning CC-L-MOF@F-Ag has the characteristics of high sensitivity and wide detection range for congo red (CR), chrysoidine (CYD) and acid orange II (AO II). • CR, CYD and AO II in six soft drinks were successfully detected with satisfactory recoveries. Surface-enhanced Raman scattering (SERS) enables azo dye monitoring become rapid and efficient. However, the high cost, low efficiency and poor recyclability of SERS substrate limit its practical application. Herein, we propose a facile strategy to develop self-cleaning carbon cloth as a high-performance and reusable SERS substrate through in-situ growth of leaf-like metal-organic framework (L-MOF) and one-step electro-deposition of flower-like Ag nanoparticles (CC-L-MOF@F-Ag) followed by chemical modification for SERS detection of congo red (CR), chrysoidine (CYD) and acid orange II (AO II) in soft drinks. Taking advantages of superhydrophobicity and SERS-active F-Ag, the prepared self-cleaning CC-L-MOF@F-Ag not only avoids the diffusion-random problem and further boosts sensitivity, but also yields excellent self-cleaning property through facile washing with water, endowing its good reusability and stability. Furthermore, this substrate can realize quantitative detection of CR, CYD and AO II with low limits of detection (0.013 μM for CR, 0.017 μM for CYD and 0.0067 μM for AO II) and wide linear detection range (0.1 – 1000 μM for CR, 0.1 – 1000 μM for CYD and 0.01 – 100 μM for AO II). Meanwhile, CR, CYD and AO II in six soft drinks were also successfully detected with satisfactory recoveries. This method provides a potential and cost-effective strategy to develop advanced SERS sensing device for effective monitoring azo dyes in soft drinks. [ABSTRACT FROM AUTHOR]

P -nitrophenol (PNP) has been widely applied to industry processing for many purposes, but the persistence and toxicity of residuum may pose risks to human health. To analyze PNP in industrial and agricultural wastewater, a versatile fluorescent probe sensing platform was proposed. In this work, we devised a fluorescence approach that utilized nitrogen, silicon co-doped carbon dots (N,Si-CDs) to monitor PNP originating from the inner filter effect (IFE). The N,Si-CDs were generated in a one-step hydrothermal synthesis, and which possessed outstanding fluorescence signal and water-dispersity. Emission at 441 nm was monitored with excitation at 360 nm using a common spectrofluorometer. The method achieved an exceptionally low limit of detection (LOD) of 0.011 μM. Furthermore, this method not only eliminates the interference from metal ions and acid ions, but also provides a potential application prospect for N,Si-CDs in the field of water monitoring. Analysis of tap and lake water led to 93.30–106.30% recoveries and <1% relative standard deviation at 2.5–25 μM PNP concentrations. Unlabelled Image • A novel fluorescence nanoprobe based on N,Si-CDs was designed for PNP detection. • The N,Si-CDs possessed outstanding fluorescence signal and water-dispersity. • This fluorometric assay has lower detection limit than other detection methods. • This fluorescence nanoprobe had been used to detect PNP in actual water samples with great recoveries. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have attracted tremendous interest due to their promising applications, including electrocatalysis originating from their unique structural features. However, it remains a challenge to prepare COFs for p-nitrophenol (PNP) and o-nitrophenol (ONP) electrocatalysis because it is quite difficult to manipulate their dimension, composition, and morphology with abundant active sites. Here, a facile ambient temperature synthesis of unique Fe 3 O 4 -based magnetic COFs nanosphere (Fe 3 O 4 @AT-COFs) with different surface morphologic structure is reported, which exhibits higher surface area, good water dispersity, long-term stability, excellent electrical conductivity and pre-concentration effect. The prepared Fe 3 O 4 @AT-COF-based electrochemical sensor is then directly employed for the simultaneous detection of PNP and ONP with a wide linear detection range of 10–3000 μM and low detection limits (LOD) of 0.2361 μM and 0.6568 μM, respectively. Meanwhile, the Fe 3 O 4 @AT-COF can be also well-applied in lake and tap water for monitoring PNP and ONP with outstanding sensitivity and reliability, which is expect to be a high-efficient electrocatalyst with great promise for signal amplification of electrochemical sensing. Image 1 • Facile synthesis of Fe 3 O 4 -based magnetic COFs with different surface morphologic structure. • COFs as the enrichment carriers of Fe 3 O 4 were employed for amplifying electrochemical sensing signals. • Fe 3 O 4 plays a dual role in magnetic attraction with the electrode and synergistic catalysis effect with COFs. • A sensitive and reliable simultaneously detection of PNP and ONP were achieved with a low limit of detection. [ABSTRACT FROM AUTHOR]

Mercury (II) ions (Hg2+), as one of the most toxic heavy metals, can cause irreversible damage to human health even at very low concentration due to its high toxicity and bioaccumulation. Herein, a facile ratiometric fluorescence nanomixture based on carbon dots‑gold nanoclusters (CDs-Au NCs) was constructed for quantitative detection of Hg2+. Lysine functionalized carbon dots (CDs) were prepared by one-pot hydrothermal method, while gold nanoclusters (Au NCs) were synthesized via using chicken egg white (CEW) as reducer and stabilizer. The novel nanomixture exhibited two strong emission peaks at 450 nm and 665 nm under 390 nm excitation, and showed pink fluorescence under UV light. Interestingly, the fluorescence of the CDs-Au NCs nanomixture was selectively response to Hg2+. The fluorescence of Au NCs at 665 nm was decreased when Hg2+ was presented in the solution, while the fluorescence of CDs at 450 nm stayed constant. The fluorescence color changed from pink to blue obviously with increasing the concentration of Hg2+, which indicated that CDs-Au NCs could be used for visual detection Hg2+ by the naked eye. Under optimal conditions, this ratiometric fluorescent sensor could detect Hg2+ accurately and possess a great sensitivity with a detection limit of 63 nM. In addition, this method was applied to detect Hg2+ in real water samples with great recoveries, suggesting its potential in practical application with simplicity, environmentally friendly and low cost. Unlabelled Image • A novel ratiometric fluorescence sensor based on CDs-Au NCs was designed for Hg2+ detection. • The sensor was constructed by simply mixing CDs and Au NCs together. • As precursors, lysine and chicken egg white were easily available and environmentally friendly. • The fluorescence color varied from pink to blue which could be clearly recognize. • This sensor had been used to detect Hg2+ in real water samples with great recoveries. [ABSTRACT FROM AUTHOR]

Novel 3D porous Ni/Cu(OH) 2 nanospheres (Ni/Cu(OH) 2 NS) were directly grown on a Ni foam (NF) via a facile one-step potentiostatic deposition synthesis route. The resultant Ni/Cu(OH) 2 NS possessed an abundance of catalytic which gave them excellent catalytic properties for the electrochemical detection of glucose in alkaline conditions. Using these NS in a promising and integrated non-enzymatic glucose sensor, a high sensitivity of 8722 μA mM−1 cm−2, a low detection limit of 1.27 μM, and a linear detection range from 10 to 1490 μM were obtained at the Ni/Cu(OH) 2 NS/NF anode. Additionally, the proposed sensor exhibited excellent anti-interference capability, good reproducibility, and long duration stability. It was successfully applied to glucose detection in human blood serum, showing excellent effectiveness. • Porous Ni/Cu(OH) 2 nanospheres supported on the Ni foam was fabricated by a facile one-step potentiostatic deposition strategy. • As-prepared Ni/Cu(OH) 2 /NF anode shows excellent catalytic activity to glucose. • The porous Ni/Cu(OH) 2 nanospheres could offer more abundant active sites and easier access to electrolyte. [ABSTRACT FROM AUTHOR]

The bactericidal properties of traditional food coatings mostly depend on the amount of fungicides present, which reduces the sustainability of food packaging. Herein, we proposed a magnetic field to precisely modulate the near-infrared (NIR) absorption activity to enhance antimicrobial coatings sustainability. Inspired by the typical grinding procedure, the assembly of CP/Fe 3 O 4 @TA nanofiber hydrogel was proposed as the coating, applying mechanical force and encouraging the collision of effective molecules of puerarin (PUE), chitosan (CS), and Fe 3 O 4 @TA NFs. This hydrogel design offers precise control over the physical and chemical properties, including appearance, viscoelasticity, and rheology. Particularly, significant changes in photothermal performance were observed as a result of magnetic regulation of NIR absorption activity. As a result, the CP/Fe 3 O 4 @TA coatings achieve effective bacteria killing performance under NIR irradiation, magnetocaloric effect, boric acid adsorption, and aggregation interference. Finally, the hydrogel coating was applied to the beef surface and serves as an effective barrier against the growth of pathogenic bacteria, thereby preserving the freshness and tenderness of the beef. The finding from this work is expected to open up a new way in active nano hydrogel coating for food preservation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

To integrate antifouling properties and good sensitivity on the sensing interface can improve the applicability of an electrochemical immunosensor. These functional regions can be integrated into a single functional peptide (functPP). The rational designed three domains in functPP were the anchoring, antifouling and gold nanoparticles (AuNPs) recognizing domains. Meanwhile, the ordered AuNPs inspired by C 15 H 23 CO-RRRRR can be recognized by AuNPs recognizing domains in functPP to enhance the intensity of detecting current. In the sensing system, the anchoring domain in functPP can be immobilized on the Au electrode by AuS interaction, while the antifouling domain undergoes strong hydration with water molecules to resist matrices, and the recognizing domains can directionally capture O-AuNPs to form a functPP-O-AuNPs complex as the core sensing element. Consequently, the complex bound to the monoclonal antibodies against zearalenone by electrostatic adsorption to develop a highly antifouling and sensitive biosensor with the ability to identify zearalenone in cereals., Competing Interests: Declaration of competing interest All the authors declare that the authors have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled “Functional peptide conjugated ordered gold nanoparticles based rational electrochemical immunosensor for highly stable and selective detection of zearalenone”., (Copyright © 2024. Published by Elsevier Ltd.)

In this study, we incorporated nanometal surface energy transfer (NSET) in lateral flow immunoassay (LFIA) and explored the relationship between fluorescence quenching efficiency and detection sensitivity to improve sensitivity of NSET-LFIA system. We developed nine gold nanoparticles (GNPs) with absorption spectrum in the range of 520-605 nm as acceptors and quantum dot microspheres (QDMs) with emission spectrum of 530, 570, and 610 nm as donors. By analyzing the overlap integral area, fluorescence quenching efficiency, and detection sensitivity of 27 donor-acceptor pairs, we observed that the larger overlap integral area led to higher fluorescence quenching efficiency and detection sensitivity. A maximum fluorescence quenching efficiency of 91.0% was obtained from the combination of GNPs at 605 nm and QDMs at 610 nm, achieving the highest detection sensitivity. We developed NSET-LFIA for the detection of T2 toxin with a limit of detection of 0.04 ng/mL, which was 10-times higher than that obtained via conventional GNP-LFIA. NSET-LFIA represents a versatile, ultrasensitive and valuable screening tool for small molecules in real samples., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

Artificial synapses and bionic neurons offer great potential in highly efficient computing paradigms. However, complex requirements for specific electronic devices in neuromorphic computing have made memristors face the challenge of process simplification and universality. Herein, reconfigurable Ag/HfO 2 /NiO/Pt memristors are designed for feasible switching between volatile and nonvolatile modes by compliance current controlled Ag filaments, which enables stable and reconfigurable synaptic and neuronal functions. A neuromorphic computing system effectively replicates the biological synaptic weight alteration and continuously accomplishes excitation and reset of artificial neurons, which consist of bionic synapses and artificial neurons based on isotype Ag/HfO 2 /NiO/Pt memristors. This reconfigurable electrical performance of the Ag/HfO 2 /NiO/Pt memristors takes advantage of simplified hardware design and delivers integrated circuits with high density, which exhibits great potency for future neural networks.

Glucagon-like peptide-1 (GLP-1) is a 30-amino acid peptide hormone that is mainly expressed in the intestine and hypothalamus. In recent years, basic and clinical studies have shown that GLP-1 is closely related to lipid metabolism, and it can participate in lipid metabolism by inhibiting fat synthesis, promoting fat differentiation, enhancing cholesterol metabolism, and promoting adipose browning. GLP-1 plays a key role in the occurrence and development of metabolic diseases such as obesity, nonalcoholic fatty liver disease, and atherosclerosis by regulating lipid metabolism. It is expected to become a new target for the treatment of metabolic disorders. The effects of GLP-1 and dual agonists on lipid metabolism also provide a more complete treatment plan for metabolic diseases. This article reviews the recent research progress of GLP-1 in lipid metabolism.

Type 2 diabetes mellitus (T2DM) has become one of the most serious public healthcare challenges, contributing to increased mortality and disability. In the past decades, significant progress has been made in understanding the pathogenesis of T2DM. Mounting evidence suggested that gut microbiota (GM) plays a significant role in the development of T2DM. Communication between the GM and the brain is a complex bidirectional connection, known as the "gut-brain axis," via the nervous, neuroendocrine, and immune systems. Gut-brain axis has an essential impact on various physiological processes, including glucose metabolism, food intake, gut motility, etc. In this review, we provide an outline of the gut-brain axis. We also highlight how the dysbiosis of the gut-brain axis affects glucose homeostasis and even results in T2DM., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Immunochromatographic assays (ICAs) have been widely used in the field detection of mycotoxin contaminants. Nevertheless, the lack of multisignal readout capability and the ability of signaling tags to maintain their biological activity while efficiently loading antibodies remain a great challenge in satisfying diverse testing demands. Herein, we proposed a novel three-in-one multifunctional hollow vanadium nanomicrosphere (high brightness-catalytic-photothermal properties)-mediated triple-readout ICA (VHMS-ICA) for sensitive detection of T -2. As the key to this biosensing strategy, vanadium was used as the catalytic-photothermal characterization center, and natural polyphenols were utilized as the bridging ligands for coupling with the antibody while self-assembling with formaldehyde cross-linking into a hollow nanocage-like structure, which offers the possibility of realizing a three-signal readout strategy and improving the coupling efficiency to the antibody while preserving its biological activity. The constructed sensors showed a detection limit (LOD) of 2 pg/mL for T -2, which was about 345-fold higher than that of conventional gold nanoparticle-based ICA (0.596 ng/mL). As anticipated, the detection range of VHMS-ICA was extended about 8-fold compared with the colorimetric signal alone. Ultimately, the proposed immunosensor performed well in maize and oat samples, with satisfactory recoveries. Owing to the synergistic and complementary interactions between distinct signaling modes, the establishment of multimodal immunosensors with multifunctional tags is an efficient strategy to satisfy diversified detection demands.

Metal oxide semiconductor (MOS)-based complementary thin-film transistor (TFT) circuits have broad application prospects in large-scale flexible electronics. To simplify circuit design and increase integration density, basic complementary circuits require both p- and n-channel transistors based on an individual semiconductor. However, until now, no MOSs that can simultaneously show p- and n-type conduction behavior have been reported. Herein, we demonstrate for the first time that Cu-doped SnO (Cu:SnO) with HfO 2 capping can be employed for high-performance p- and n-channel TFTs. The interstitial Cu + can induce an n-doping effect while restraining electron-electron scatterings by removing conduction band minimum degeneracy. As a result, the Cu 3 atom % :SnO TFTs exhibit a record high electron mobility of 43.8 cm 2 V -1 s -1 . Meanwhile, the p-channel devices show an ultrahigh hole mobility of 2.4 cm 2 V -1 s -1 . Flexible complementary logics are then established, including an inverter, NAND gates, and NOR gates. Impressively, the inverter exhibits an ultrahigh gain of 302.4 and excellent operational stability and bending reliability.

Sensory information transmitted to the brain activates neurons to create a series of coping behaviors. Understanding the mechanisms of neural computation and reverse engineering the brain to build intelligent machines requires establishing a robust relationship between stimuli and neural responses. Neural decoding aims to reconstruct the original stimuli that trigger neural responses. With the recent upsurge of artificial intelligence, neural decoding provides an insightful perspective for designing novel algorithms of brain-machine interface. For humans, vision is the dominant contributor to the interaction between the external environment and the brain. In this study, utilizing the retinal neural spike data collected over multi trials with visual stimuli of two movies with different levels of scene complexity, we used a neural network decoder to quantify the decoded visual stimuli with six different metrics for image quality assessment establishing comprehensive inspection of decoding. With the detailed and systematical study of the effect and single and multiple trials of data, different noise in spikes, and blurred images, our results provide an in-depth investigation of decoding dynamical visual scenes using retinal spikes. These results provide insights into the neural coding of visual scenes and services as a guideline for designing next-generation decoding algorithms of neuroprosthesis and other devices of brain-machine interface.

A sensitive immunochromatographic assay (ICA) using time-resolved fluorescence microspheres (TRFMs) coupled with an indirect-labeling mode was developed for simultaneously determining 22 kinds of β-lactams in milk samples. The TRFMs labeled anti-receptor monoclonal antibodies (mAbs) conjugated to penicillin-binding proteins (PBPs) as ternary TRFMs-mAb-PBPs (TMP) nanoscaffolds provide excellent solubility, brightness, and stability. Thanks to the fact that they not only fully expose the binding sites of PBPs, thereby enhancing the biological affinity of PBPs towards the target, but also generated superb fluorescence signals, the versatile TMP manifested unique possibilities as efficient probes for ICA with remarkable enhancement in sensitivity in β-lactams screening. The results showed that the standard curves of the 22 varying β-lactams displayed linearity in their respective concentration ranges (R 2 > 0.98), with the cutoff values of 1-100 ng/mL. The constructed TMP-ICA was successfully applied to the analysis of real milk, with consistent results compared with liquid chromatography-tandem mass spectrometry (LC-MS), providing an effective method for sensing β-lactams in food matrices., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

To avoid false negative results due to the low cross-reactivity rate (CR) in rapid immunoassay, a group-specific antibody with homogeneous CR toward target compounds is needed for accuracy. In this study, tylosin (TYL) and tilmicosin (TM) were selected as model molecules. Firstly, two-dimensional similarity, electrostatic potential energy, spatial conformation and charge distribution of the haptens TYL-CMO, TYL-6-ACA, TYL-4-APA, TYL-CHO and DES-CMO and target compounds of TYL and TM were obtained using Gaussian 09W and Discovery Studio. The optimal hapten was DES-CMO because it is the most similar to TYL and TM. Subsequently, the mAb 14D5 cell line was obtained with IC 50 values of 1.59 and 1.72 ng/mL for TYL and TM, respectively, and a CR of 92.44%. Finally, amorphous carbon nanoparticles (ACNPs) were conjugated with mAb 14D5 to develop an accurate lateral flow immunoassay (LFA) for detection of TYL and TM by the reflectance value under natural light. The recoveries of TYL and TM ranged from 77.18 to 112.04% with coefficient of variation < 13.43%. The cut-off value in milk samples was 8 ng/mL, and the limits of detection were 11.44, 15.96, 22.29 and 25.53 μg/kg for chicken muscle, bovine muscle, porcine muscle and porcine liver samples, respectively, and the results being consistent with HPLC-UV. The results suggest that the developed LFA is accurate and potentially useful for on-site screening of TYL and TM in milk and animal tissue samples., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Nanomaterials-based immunochromatographic assays (ICAs) are of great significance in point-of-care testing (POCT), yet it remains challenging to explore low background platforms and high chromogenic intensity probes to improve detection performance. Herein, we reported a low interference and high signal-to-noise ratio fluorescent ICA platform based on ultrabright persistent luminescent nanoparticles (PLNPs) Zn 2 GeO 4 : Mn, which could produce intense photoluminescence at 254 nm excitation to reduce background interference from ICA substrates and samples. The prepared immunosensor was successfully applied in T-2 toxin detection with a remarkable limit of detection of 0.025 ng/mL, which was 22-fold more sensitive compared with that of traditional gold nanoparticles. Ultimately, a portable 3D-printed detection device equipped with a smartphone analyzing application was fabricated for quantitative readout in POCT, achieving favorable recoveries in practical sample detection. This work provides a creative attempt for ultrabright PLNP-based low background ICA, and it also guarantees its feasibility in practical POCT.