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Monitoring cell metabolism is crucial for understanding cell life activity and cytopathic mechanism. Glucose and oxygen are very important parameters for cell metabolism. In this work, core/shell nanomaterials as novel tricolor ratiometric luminescence nanosensors were prepared for real-time monitoring of intracellular oxygen and glucose levels. The nanosensors were achieved by covalently embedding of red emitting oxygen probes and yellow emitting reference probes into the hydrophobic cores and covalently grafting blue emitting glucose probes onto hydrophilic shells. This system realized simultaneous detection of glucose and oxygen through two different luminescent signals without enzyme assistance, and the two kinds of detection signals didn’t interfere with each other. The nanosensors could sensitively detect glucose in the range of 0.01 to 5.0 mM and simultaneously detect dissolved oxygen in the range of 0.05 to 39.3 mg/L, indicating the suitableness for intracellular glucose and oxygen monitoring. Because of the small sizes (

Polymeric microfibers, particularly the fluorinated copolymers’ fibers, are promising functional materials for photoelectric devices, sensing, and energy storage due to their various surface characteristics. However, to obtain the high fluorine content copolymer-based fibers with considerable uniformity is likely to be especially challenging, which seriously debilitates their applications in sensor devices. Herein, for the first time, we presented a high fluorine content platinum porphyrin-grafted poly(isobutyl methacrylate-co-dodecafluoroheptyl methacrylate) copolymers (PtTFPP-p(IBM-co-DFHMA)) microfibrous thin-films used as optical oxygen sensors. The porous thin-film frameworks were formed of uniform microfibers, which afforded an exceptional improvement in sensitivity and exhibited 584% higher sensitivity than the solid sensing film owing to the large specific surface area, porous structures and oxygen diffusion enhancement by fluorine elements. Additionally, the remarkable emission intensity-changing characteristic of the microfiber sensing film under various air pressures facilitates convenient visualization of pressure distributions on film surface. The characteristics are particularly important for the computational fluid dynamics simulations in various sensing fields such as unsteady flow visualization and unsteady pressure measurements, etc. Owing to its attractive advantages and versatile performance, fluorine-containing copolymers fibers are expected to provide a new strategy for the rational design of high performance gas sensor devices.

EDTA-bonded multi-connected carbon-dots (EDTA–C-dots) were prepared from carbon dot precursors and complexed with Eu3+ to give Eu3+-coordinated EDTA-bonded multi-connected carbon dots (Eu–EDTA–C-dots). Whereas EDTA–C-dots were readily soluble in DMSO, Eu–EDTA–C-dots could not be easily dissolved in DMSO, water, or other common organic solvents. The newly prepared materials were thoroughly characterized. The X-ray diffraction results showed that no crystalline phase of Eu oxides (europium oxide or europium hydroxide) could be observed in Eu–EDTA–C-dots. The infrared and UV-Vis spectra showed that coordination with Eu3+ ions did not damage the structure of the EDTA–C-dots. It was found that EDTA could be easily grafted on the surface of carbon dots and EDTA had minimal influence on the photoluminescence of the carbon dot matrix. In contrast, the existence of Eu3+ ions strongly quenched the photoluminescence of Eu–EDTA–C-dots. The measured and fitted decay lifetime indicated that Eu–EDTA–C-dots possessed two photoluminescence decay processes, i.e., radiative recombination and non-radiative recombination.

Mono-dispersed polystyrene-based microspheres with diameters about 1 μm encapsulating rhodamine moieties as oxygen insensitive internal reference probes and platinum octaethylporphyrin units as oxygen sensitive probes were synthesized as new ratiometric oxygen sensors (Rhod-PtOEP-PS). The dual luminophors of rhodamines and platinum porphyrin moieties exhibited emissions maxima at 585 nm and 644 nm, respectively. The microspheres showed good oxygen sensing properties in different oxygen partial pressures (pO2) and dissolved oxygen (DO) concentrations. It was found the oxygen probes and reference probes in microspheres showed higher photo-stability than their corresponding free fluorophores in solution. The microspheres also showed good sensitivity for air-pressure and cellular oxygen in cell culture medium. These microspheres were used to detect DOs in a few kinds of liquids including some daily drinks and it was found the measured errors were within positive/negative 11% as compared with the measured results using traditional oxygen electrodes.

In this work, we presented the robust and magnetically recoverable dual sensor particles that are capable of real-time monitoring of dissolved oxygen (DO) and glucose concentrations in aqueous solutions. The dual sensor consists of glucose oxidase-functionalized polyethylenimine-coated Fe3O4 particles (Fe3O4@PEI-GOD) and sub-micro-sized Fe3O4-modified poly(Platinum porphyrin-co-Styrene) ((PtTFPPMA-PS)@Fe3O4) fluorescent spheres. The dual sensing functions originate from the cascade catalysis amplification driven by the recyclable Fe3O4@PEI-GOD particles and glucose oxidase consumption of oxygen in the process of glucose oxidation. Consequently, the (PtTFPPMA-PS)@Fe3O4 fluorescent spheres exhibited higher fluorescence intensity due to the effective alleviation of fluorescence quenching effect raised from the decrease of DO. The remarkable fluorescence intensity-changing characteristics of the solutions facilitate convenient identification of oxygen concentrations and glucose concentrations even with naked eyes. Thanks to the magnetically recoverable superiority, the recycle study proved that the multifunctional particles could be repeatedly utilized without significant catalytic activity loss after 10 cycles. Interestingly, the sensing film comprising the (PtTFPPMA-PS)@Fe3O4 fluorescent spheres can also be applied to the unsteady pressure measurement and unsteady air flow visualization due to its remarkable light intensity-changing features.

Sensitivity enhancement of optical oxygen sensors is crucial for the characterization of nearly anoxic systems and oxygen quantification in trace amounts. In this work, for the first time we presented the introduction of silver nanowires (AgNWs) as a sensitivity booster for optical oxygen sensors based on AgNWs–palladium octaethylporphine–poly(methyl methacrylate) (AgNWs@PdOEP–PMMA) microfiber mats prepared by electrospinning. Herein, a series of sensing microfiber mats with different loading ratios of high aspect ratio AgNWs were fabricated, and the corresponding sensitivity enhancement was systematically investigated. With increasing incorporated ratios, the AgNWs@PdOEP–PMMA-sensing microfiber mats exhibited a swift response (approx. 1.8 s) and a dramatic sensitivity enhancement (by 243% for the range of oxygen concentration 0−10% and 235% for the range of oxygen concentration 0–100%) when compared to the pure PdOEP–PMMA microfiber mat. Additionally, the as-prepared sensing films were experimentally confirmed to be highly photostable and reproducible. The advantages of AgNW-induced sensitivity enhancement could be useful for the rational design and realization of revolutionary highly sensitive sensors and expected to be readily applicable to many other high-performance gas sensor devices.

Triboelectric nanogenerator/supercapacitor (TENG-SC) is believed to have great potential for wearable/portable bio-motion energy harvesting/storage electronics, but many TENGs could rarely be satisfactory to wearable electronics because of their poor wearability and complex configurations. Herein, a round-tripping-knitting strategy is devised to directly knit flexible PTFE yarn closing around polydimethylsiloxane/MnO2 nanowire (PDMS/MnO2NW)-coated conductive carbon cloth yarns (CCT@PDMS/MnO2NW) that can be used as wearable TENG textile to harvest bio-motion energy. Superior power generation performance was obtained by modulating the dielectric permittivity of PDMS/MnO2NW elastomer based on variations in the mass-loading of MnO2NW. The obtained TENG textile can convert various forms of bio-motion energy into electrical signal and the maximum output voltage of about 380 V can be obtained and easily light up 200 serially connected LEDs. Additionally, all-solid-state yarn-type asymmetric supercapacitor was woven with TENG and act as energy storage unit, which demonstrates high volumetric energy density and excellent cyclic stability. Because of the flexible all yarn-type structure of the entire system, the SC and TENG can be easily woven into cloth to continuously harvest and store bio-motion energy, which demonstrates great convenience and immense applications as wearable, lightweight, comfortable continuous bio-motion energy harvesting/storage device and versatile pressure sensing.

In this work, we presented a facile and cost-effective approach to fabricate novel PtTFPP/PDMS micro-pillar array (MPA) sensor film with I0/I100 for gaseous oxygen and dissolved oxygen are 288 and 84, respectively. The sensitivity of the sensor film exhibited over ∼30-fold increment when compared with contemporary PtTFPP/PDMS-based oxygen sensors. The detection limit was as low as 0.10 μmol/L, which means that the ultrasensitive sensor films enable reliable monitoring of dissolved oxygen (DO) within nanomolar concentration ranges that are particularly difficult to achieve in previous works. Furthermore, the remarkably light intensity-changing characteristic of the sensing film under lower O2 partial pressures facilitates convenient identification of O2 concentrations even with the naked eye. We believe that the proposed device could be a promising candidate in various oxygen sensing fields such as nearly anoxic systems, unsteady pressure measurement and unsteady flow visualization, etc.

Control of water adhesion is important for superhydrophobic surfaces in various applications. In this work, we present a facile approach to prepare superhydrophobic polydimethylsiloxane (PDMS) with patternable and controllable water adhesion capabilities. Surface grafting of N-isopropylacrylamide was primarily exploited to regulate the PDMS template morphologies, either by tuning the ultraviolet irradiation duration or adopting repeated grafting process. The surface topologies of as-prepared PDMS templates can be flexibly constructed with roughness degrees ranging widely from 1.5 to 738.7 nm. Followed with covering of carbonyl iron particles (CIP) on the template surface, the duplicated PDMS substrate can thus recur the surface topology incorporated with CIP onto the upper surface, leading to the feasibility to regulate diverse water adhesion capabilities. Owing to the synergistic effect by the surface roughness and CIP incorporation, the water adhesion capabilities of the PDMS substrates can be flexibly tuned ranging from droplet pinning to excellent water repellency. The presented strategies were further developed to create PDMS substrates with patterned water adhesion for controllable micro-droplet transportation or rapidly programmable droplet localizations. We believe that the environmentally friendly method can offer as a convenient yet cost-effective tool for future microfluidic devices, biochemical analysis, etc.

Organic–inorganic hybrid 3-(trimethoxysily)propylmethacrylate-co-platinum porphyrin-co-methacrylolsobutyl-polyhedral oligomeric silsesquioxane (TPMA-PtTPP-POSS) copolymer films were synthesized and applied as high-performance oxygen sensors. High sensitivity and fast response characteristics originate from the POSS-containing copolymer composition and wormlike structures. The wormlike structures composed of the POSS-containing copolymers self-assembled on the film surface can ensure the homogeneous dispersion of PtTPP and can be perturbed by a trace oxygen environment. Compared with the state-of-the-art PtTPP-TPMA film, the TPMA-PtTPP-POSS copolymer sensors exhibit a swift response (approx. 0.6 s), long-term stability, higher sensitivity (increased by 4-fold), and a relatively large dynamic range, etc. We believe that the POSS-containing hybrid films should provide a new strategy for designing sensitive and fast responding optical oxygen sensors.

The aim of the present work is to investigate the effects of Al2O3 content on both the structure and crystallization behavior of CaO–B2O3–SiO2 (CBS) glass composition using NMR, FT-IR and DSC. The density experimental results showed that the density (ρ) of glasses decreased linearly with increasing Al2O3 content, while the molar volume (Vm) of the glasses increased linearly. The NMR revealed that the Al occurred in the forms of AlIV, AlV and AlVI units. With the increasing Al2O3 content, the amount of Al species show little change, the relative amount of BIIIa and BIIIs units increases while the BIV units decrease, and the Q4 structural units increases clearly but the Q3 decreases. Further, crystallization peaks of CBS glasses shift to higher temperatures, indicating that Al2O3 addition can suppress crystallization of CBS glasses.

Integrating an oxygen-sensitive probe (OSP) onto a three-dimensional (3D) microstructure substrate is a plausible technique to significantly improve the sensitivity of oxygen sensors. Despite the fact that polydimethylsiloxane (PDMS) matrices are regarded as the ideal sensory support, there are still no reports on an OSP functionalized flexible PDMS-based micropillar array (PDMS-MPAs) film as an optical oxygen sensor with capabilities to efficiently improve the sensor's overall performance, e.g. sensitivity, detection limit and stability against photo-bleaching. Herein, we reported the covalent bonding of a functional copolymer of platinum porphyrin (PtTPP)/3-(trimethoxysily)propylmethacrylate (PtTPP/TPMA) as the OSP on the surface of hydroxyl-modified PDMS-MPAs through a “grafting reaction” between PtTPP/TPMA and PDMS-MPAs. The homogeneous dispersion and well-isolated arrangement of the PtTPP/TPMA OSP on the 3D PDMS-MPA surface can ensure that the grafted OSP efficiently quenches the oxygen molecules. Consequently, the 3D PtTPP/TPMA-PDMS-MPA sensor film gives rise to a high fluorescence quenching efficiency of about 95% at 1 atm O2 (I0/I100 = 23) and 96% in aqueous solution (I0/IO2satu = 16) with an excellent linear Stern–Volmer plot (ksv = 0.1 h Pa−1, R2 = 0.997 in gas atmosphere and ksv = 12.8 mmol−1 L, R2 = 0.999 in aqueous solution, respectively), excellent reversibility and an ultra-low detection limit (4.7 μmol L−1) when compared with state-of-the-art PDMS-based oxygen sensors. Apart from the competitive sensitivity, the highly durable, reusable superiorities of the 3D PtTPP/TPMA-PDMS-MPA film can further facilitate the exploration and realization of the presented strategy for future oxygen sensor applications, such as the characterization of nearly anoxic systems in harsh environments.

Large-scale, uniform silver nanowires (AgNWs) with diameter of 30 nm and ultra-high aspect ratio up to 4000 were obtained by adding Cu2+ and Fe3+ to the AgNWs synthesis. AgNWs were longer at higher concentration of Cu2+ and better uniformity in the presence of both Fe3+ and Cu2+. Finding indicate that by simply controlling Cu2+/Fe3+ molar ratios in the reaction process, the high yield (98%), ultra-high aspect ratio (over 4000) and large-scale (over 50 g per pot) production of AgNWs can be obtained. Additionally, embedding the ultra-high aspect ratio AgNWs into polyvinyl alcohol (PVA) matrices, novel AgNWs@PVA flexible transparent conductor films (TCFs) with high-electrical conductivity performance was fabricated. This method improved the production efficiency of ultra-high aspect ratio AgNWs and could be applied to high performance TCFs; thus having major commercial implications.

The development of flexible pressure sensors has attracted increasing research interest for potential applications such as wearable electronic skins and human healthcare monitoring. Herein, we demonstrated a piezoresistive pressure sensor based on AgNWs-coated hybrid architecture consisting of mesoscaled dome and microscaled pillar arrays. We experimentally showed that the key three-dimensional component for a pressure sensor can be conveniently acquired using a vacuum application during the spin-coating process instead of a sophisticated and expensive approach. The demonstrated hybrid structure exhibits dramatically improved sensing capability when compared with the conventional one-fold dome-based counterpart in terms of the sensitivity and detectable pressure range. The optimized sensing performance, by integrating D1000 dome and D50P100 MPA, reaches a superior sensitivity of 128.29 kPa-1 (0-200 Pa), 1.28 kPa-1 (0.2-10 kPa), and 0.26 kPa-1 (10-80 kPa) and a detection limit of 2.5 Pa with excellent durability. As a proof-of-concept, the pressure sensor based on the hybrid configuration was demonstrated as a versatile platform to accurately monitor different kinds of physical signals or pressure sources, e.g., wrist pulse, voice vibration, finger bending/touching, gas flow, as well as address spatial loading. We believe that the proposed architecture and developed methodology can be promising for future applications including flexible electronic devices, artificial skins, and interactive robotics.

Side-chain polymers have the potential to be excellent dopant-free hole-transporting materials (HTMs) for perovskite solar cells (PSCs) because of their unique characteristics, such as tunable energy levels, high charge mobility, good solubility, and excellent film-forming ability. However, there has been less research focusing on side-chain polymers for PSCs. Here, two side-chain polystyrenes with triphenylamine substituents on carbazole moieties were designed and characterized. The properties of the side-chain polymers were tuned finely, including the photophysical and electrochemical properties and charge mobilities, by changing the positions of triphenylamine substituents on carbazole. Owing to the higher mobility and charge extraction ability, the polymer P2 with the triphenylamine substituent on the 3,6-positions of the carbazole unit showed higher performance with power conversion efficiency (PCE) of 18.45%, which was much higher than the PCE (16.78%) of P1 with 2,7-positions substituted. These results clearly demonstrated that side-chain polymers can act as promising HTMs for PSC applications and the performance of side-chain polymers could be optimized by carefully tuning the structure of the monomer, which provides a new strategy to design new kinds of side-chain polymers and obtain high-performance dopant-free HTMs.

Based on a facile, environment-friendly, simple one-step method in aqueous solution, a novel dumbbell-like silver citrate (Ag3C6H5O7, SC) microstructure (DSCM) was successfully synthesized for the first time. The DSCM was confirmed by SEM, and further structurally characterized by XRD. A possible formation mechanism of DSCM has been briefly discussed based on the morphology evolution of SC microstructures at different growth stages. Moreover, surface enhanced Raman scattering characterization revealed significantly higher Raman signal for the absorbed 2-mercaptopyridine (2-MPY) molecule and super sensitivity by using the as-fabricated DSCM substrate.

Cubic Co3O4 supported Au nanocomposites have been synthesized via a facile impregnation method. The Au/Co3O4 exhibited excellent catalytic activity for the reduction of 4-nitrophenol (TOF = 9.83 min−1). The unique structure and high catalytic performance make the materials highly promising candidates for diverse applications in the area of catalysis.

To fabricate the conductive composites with the low resistivity required for conductive films, a multi-layer network of AgNWs must be produced which may not be cost effective. Recently, we have counteracted the problem by using AgNWs and Ag-microsheets to form novel overlapping-junctions-nanostructures, which can significantly improve the electrical properties of conductive films. Subsequently, low-cost, highly-conductivity flexible conductive films were fabricated using Ag-microsheets, Ag-nanowires (AgNWs) and polyvinyl alcohol (PVA) as conducting agents. Interestingly, the interconnected AgNWs and Ag-microsheets within the reciprocal architecture could effectively accommodate strain and show good conductivity under stretching (stretchability of 35%) before they ruptured into patches; thus having major commercial implications.

Novel hierarchical multipod silver citrate complex (SCC) microcrystals have been successfully synthesized in aqueous solution for the first time. The multipod SCC microcrystals with an average size of 10 μm are composed of well-crystallized multiple arms, which grow from the lateral sidewalls of the bigger SCC seeds. A study on surface enhanced Raman scattering (SERS) activity is also carried out on the novel hierarchical multipod SCC microcrystals. The results reveal that the prepared SCC microcrystals showed excellent performance and super sensitivity as a SERS substrate, indicating the potential application in SERS-related detection.

Lead-free (1−x)(Ba 0.85 Ca 0.15 )(Ti 0.9 Zr 0.1 )O 3 -xBa(Mg 1/3 Nb 2/3 )O 3 (BCZT-BMN) (x=0.05, 0.10, 0.15, 0.20) ceramics were fabricated by conventional solid-state reaction. The effect of Ba(Mg 1/3 Nb 2/3 )O 3 (BMN) addition on structure and electrical properties of BCZT ceramics were studied. The results show that the BCZT-BMN ceramics possess rhombohedral phase at x=0.05, orthorhombic and rhombohedral phases coexist at x=0.10, 0.15, 0.20. High Curie temperature (T c ) maintained over 300 °C at the compositions x=0.05 and 0.10. The samples at x=0.05 exhibit good ferroelectric properties. This work offers an effective way to adjust the range of service temperature of BCZT by BMN addition.

Unique coral-like silver citrate (Ag3C6H5O7, SC) microstructures (CSCM), with a surface roughened by numerous short needle points in a dense array, have been fabricated via a one-step strategy in a...