In this work, we present a novel strategy for developing solid-state luminescence turn-on sensors by constructing indicator displacement assays (IDAs) within a covalent organic framework (COF) composed of 2,4,6-triformylphloroglucinol (Tp) and 5, 5'-diamino-2, 2'-bipyridine (Bpy) ligands. To illustrate our strategy, a robust electron-deficient COF was synthesized through the post-synthetic N-alkylation of its bipyridyl units. The cationic N-alkylated bipyridyl units served as receptors, while the fluorescent indicator, anionic 8-anilino-1-naphthalenesulfonate (ANS-), was incorporated within the framework via anion exchange. The resulting host-guest hybrid exhibited negligible fluorescence due to the efficient electron donor-receptor charge-transfer (CT) quenching of the ANS- indicators. Upon exposure to the strong electron-donating analyte triethylamine (TEA), the competitive CT interaction between the ANS- indicators and TEA with the cationic bipyridyl receptors initiates the indicator displacement process, leading to the significant fluorescence activation of ANS-. This rapid and sensitive fluorescence turn-on response in dioxane enables efficient detection of TE{Wang, 2020 #79}A with a limit of detection (LOD) of 0.95 nM. Moreover, practical applicability was demonstrated through the fabrication of test strips exhibiting visually observable solid-state fluorescence at TEA concentrations as low as 1 μM. This work presents the first demonstration of confining IDAs within COFs for solid-state luminescence turn-on sensing of TEA. It not only establishes a general approach for developing turn-on TEA sensors but also broadens the utility of COFs as versatile platforms for advanced sensing applications.

Surface-Enhanced Raman Spectroscopy (SERS) is highly attractive as an analytical technique owing to its high sensitivity, distinctive molecular specificity, and speed of analysis. It offers the potential to match the sensitivity and molecular specificity of established techniques like Gas Chromatography–Mass Spectrometry in a more affordable, faster, and portable format, providing unique solutions for challenging analytical problems such as bedside diagnostics and in-field forensic analysis. Despite these benefits, SERS currently remains a specialized technique and has not yet successfully entered the mainstream of analytical chemistry. This transition is hindered primarily by challenges in achieving robust, reliable, and especially quantitative measurements in real-world applications. Achieving quantitative SERS requires addressing core issues arising from the heterogeneous nature of enhancing substrates and the complexity of real-life samples. This perspective summarizes the fundamental challenges associated with signal variability and matrix interference. It then details modern strategies focused on standardizing performance metrics, with particular emphasis on the newly proposed SERS Performance Factor for substrate evaluation, alongside the development of advanced quantification methods (e.g., internal standardization and digital SERS) and rapid sample pretreatment protocols. Finally, emerging prospects, including the deployment of Artificial Intelligence for enhanced analysis and advancements in deep-tissue SERS sensing, are explored as critical drivers for integrating SERS into routine analytical practice.

Single-component photocatalytic materials generally exhibit poor utilization of visible light and inefficient charge separation. To address these limitations, a series of g-C3N4/Bi2MoO6 heterojunction composites were fabricated via a facile stirring-assisted heating-evaporation method. Structural and spectroscopic characterization revealed intimate interfacial coupling between g-C3N4 and Bi2MoO6 accompanied by evident interfacial electronic interaction. Under visible-light irradiation, the 30% g-C3N4/Bi2MoO6 composite exhibited the highest catalytic activity toward Rhodamine B (RhB) degradation, with an apparent rate constant of 0.01922 min-1. This rate constant was 4.14 and 7.09 times higher than those of pristine g-C3N4 and Bi2MoO6, respectively. Photoelectrochemical measurements further confirmed that the constructed heterojunction significantly accelerated charge-carrier kinetics and mobility while effectively suppressing electron-hole recombination. Radical-trapping experiments combined with band-structure analysis indicated that holes (h+) are the dominant active species for RhB oxidation, with ˙O2 - serving as a secondary reactive species and ˙OH contributing only marginally. The enhanced photocatalytic activity arises from efficient interfacial charge separation and directional charge migration.

The abundant hydrophilic hydroxyl groups and porous structure make wood highly susceptible to moisture absorption from the environment, leading to issues such as deformation and decay. This work aims to in situ construct a multifunctional organosilicon/organic hybrid resin coating on the wood surface derived from the click reaction of polymethylhydrosiloxane (PMHS), using PMHS, divinylbenzene (DVB), and the Karstedt catalyst. At room temperature, through the Si-H addition click reaction between PMHS and DVB, a cross-linked and rigid hybrid resin coating with a hardness of 94.00 HA is fabricated on the wood surface. Simultaneously, a dehydrogenation click reaction takes place between the Si-H groups of PMHS and the -OH groups on the wood surface, anchoring the hybrid resin coating to the wood via covalent bonds. These endow the hybrid resin coating with excellent mechanical stability. The low surface energy of organosilicon resin in the hybrid coating affords the modified wood with good waterproofness by decreasing the 24 h water absorption rate from 78.6% to 13.9%. Most importantly, the coating remains hydrophobic even after being immersed in an alkaline solution (pH = 13) for 24 h. SEM images of the coating after alkaline corrosion indicate that while the Si-O-Si skeleton of the organosilicon component is partially dissolved due to its susceptibility to alkali, the hydrophobic organic resin skeleton remains intact, imparting good alkali resistance to the hybrid resin coating. In summary, the organosilicon/organic hybrid coating constructed via the click reaction of PMHS on the wood surface effectively addresses the issue of poor alkali resistance commonly associated with traditional organosilicon coatings.

ABSTRACT The unique luminescent properties of lanthanides have driven significant advances in remote temperature sensing. However, conventional intensity ratio thermometers governed by Boltzmann equilibrium require high temperatures, often exceeding safe restrictions for biological applications. Meanwhile, luminescence intensity ratio thermometers based on multiple emission centers also suffer from poor stability and batch‐to‐batch variation, undermining measurement reliability. Here, we introduce a novel single‐emission‐center BaFCl:Sm 2+ thermometer specifically for applying in biological sensing. Kinetic rate equations and experimental results indicate that the thermal crossover between the 4f 5 5d 1 and 5 D J states of Sm 2+ is mainly responsible for the thermal luminescence performance. More importantly, our thermometer shows high relative sensitivity (4.57% K −1 , 293 K) and excellent temperature resolution (0.13, 293 K) in the physiological range of 293–333 K. Furthermore, laser spot heating and intracellular experiments confirm this reliable temperature‐dependent response at the luminescence wavelengths of 643 and 688 nm. These results highlight the promise for precise temperature sensing in biological systems.

The unique luminescent properties of lanthanides have driven significant advances in remote temperature sensing. However, conventional intensity ratio thermometers governed by Boltzmann equilibrium require high temperatures, often exceeding safe restrictions for biological applications. Meanwhile, luminescence intensity ratio thermometers based on multiple emission centers also suffer from poor stability and batch-to-batch variation, undermining measurement reliability. Here, we introduce a novel single-emission-center BaFCl:Sm2+ thermometer specifically for applying in biological sensing. Kinetic rate equations and experimental results indicate that the thermal crossover between the 4f55d1 and 5DJ states of Sm2+ is mainly responsible for the thermal luminescence performance. More importantly, our thermometer shows high relative sensitivity (4.57% K-1, 293 K) and excellent temperature resolution (0.13, 293 K) in the physiological range of 293-333 K. Furthermore, laser spot heating and intracellular experiments confirm this reliable temperature-dependent response at the luminescence wavelengths of 643 and 688 nm. These results highlight the promise for precise temperature sensing in biological systems.

ABSTRACT Although conductive composites based on aramid nanofibers (ANFs) have been extensively investigated for flexible electronics, the majority of reports concentrate solely on single‐function optimization and are unable to meet the requirements of integrated multifunctional systems in next‐generation smart devices. Herein, a high‐performance silver@aramid nanofiber (Ag@ANF) composite film with a 3D continuous conductive network is fabricated via in situ reduction, vacuum filtration, and hot pressing. The optimized Ag@ANF‐4H composite film exhibits an electrical conductivity of 176 018 S m − 1 and a fracture stress of 36.4 MPa, achieving an excellent balance between electrical and mechanical properties. Based on the Ag@ANF composite film, we have successfully demonstrated six versatile applications, including a wearable electrothermal device with tensile strain over 200%, an Ag@ANF/polyethylene (PE) electrothermal actuator with a bending curvature of 1.89 cm −1 , an X‐band electromagnetic interference (EMI) shielding material with 77 dB effectiveness, a self‐powered triboelectric nanogenerator (TENG) sensor, and two machine learning‐integrated intelligent systems for handwriting recognition and material sorting, which enable real‐time character recognition and automatic metal/non‐metal sorting. This work not only improves the conductive performance of ANF‐based composites but also achieves versatile applications of a single material, broadening the application scope of ANF‐based composites in intelligent flexible electronics.

The selective separation and detection of benzene from toluene remains a critical challenge due to their structural similarity and the toxicity of benzene. In this work, we develop a novel composite substrate, PIZA-AgNW, consisting of a metal-organic framework (MOF), silver nanowires (AgNWs), and filter paper, fabricated via liquid-phase epitaxy (LPE). This substrate enables highly selective and real-time detection of benzene from toluene using tandem surface-enhanced Raman spectroscopy (SERS) and quartz crystal microbalance (QCM) analysis. The LPE method affords precise control of MOF thickness and pore structure, enhancing molecular selectivity for Raman detection. By correlating Raman intensity with QCM-derived mass changes, we achieve real-time monitoring of adsorption/desorption dynamics and quantify both equilibrium and nonequilibrium separation factors. Notably, a high equilibrium separation factor (alpha e) of 134 was obtained for a 1:1 benzene/ toluene mixture. This work demonstrates a practical strategy for integrating structural selectivity with real-time sensing and offers broad potential for the dynamic monitoring of volatile organic compounds (VOCs) in environmental and industrial applications.

The widespread adoption of rechargeable zinc-air batteries (ZAB) is hindered by slow oxygen evolution reaction (OER) kinetics and poor durability of cathode catalysts. This study uses flake-like MXene nanosheets as a base material and creates a 3D porous scaffold with vertical channels via an ice templating method. Transition metal oxides (NiFeMnOx) were deposited onto this MXene framework and annealed, resulting in a nanocomposite with a high surface area and mechanical stability. The 3D structure promotes efficient ion infiltration at the electrode-electrolyte interface, enhancing oxygen mass transport and reaction kinetics. The NiFeMnOx catalyst shows bifunctional catalytic activity, reducing overpotentials and improving cycling stability for both oxygen reduction and evolution reactions. The cathode material exhibits an overpotential of only 325 mV at 10 mA cm-2 and a low charge transfer resistance of 25 Omega. A liquid ZAB with this MXene/NiFeMnOx cathode demonstrated a cycling lifespan of 120 h, outperforming commercial Pt/C-RuO2 air electrodes. This approach combines material optimization with a 3D porous structure, improving mass transport and charge transfer, thus advancing ZAB performance.

High-frequency operating conditions impose stringent requirements on soft magnetic composites, including high magnetic permeability, low core loss, and efficient heat dissipation. In this work, flake-shaped Fe-Si-Al/AlN soft magnetic composites were fabricated via plasma-assisted ball milling (PABM) through synergistic regulation of powder morphology and insulating phase coating. Microstructural characterization reveals that a continuous and dense AlN coating is formed on the surface of Fe-Si-Al flakes during PABM, exhibiting strong interfacial bonding with an interfacial binding energy of −3.34 eV. The addition of AlN significantly regulates the overall properties of the composites. The optimal performance is achieved at 4 wt% AlN, where the volume electrical resistivity reaches 95.7 Ω m (over 15 times higher than the uncoated sample), the total core loss reduces to 122.8 kW/m3 (10 mT, 500 kHz), and the thermal conductivity increases to 37.3 W m−1 K−1. Mechanistic analysis indicates that the flake structure effectively confines the eddy-current paths, enhancing the high-frequency magnetic response, while the AlN coating blocks interparticle conductive pathways and constructs efficient phonon transport channels to enhance thermal conductivity. The synergistic effect of these two factors enables simultaneous improvement of magnetic properties and thermal management performance, providing experimental and theoretical guidance for the design of high-frequency soft magnetic composites.

Industrial wastewater contains high levels of chloride (Cl-) ions, which lead to environmental issues and equipment corrosion. Mayenite (Ca12Al14O33) has a strong ability to adsorb Cl-due to its transformation from a metastable nanocage-like structure to a thermodynamically more stable hydration layered structure. However, its practical application is constrained by limited structural activity and sluggish reaction kinetics. To address these limitations, titanium-doped mayenite (Ti-doped Ca12Al14O33, CAOT) was synthesized via the substitution of Ca sites by Ti within the Ca12Al14O33 crystals. The incorporation of 3 % Ti (CAOT3) optimized the phase composition and surface morphology, resulting in a significantly higher Cl-removal efficiency of 78.27 % compared to the 51.1 % removal obtained by the pristine CAO. In the treatment of electroplating wastewater, CAOT3 not only effectively removes Cl-but also has the capability to synergistically treat various pollutants, such as SO42-and heavy metals. The enhanced chloride removal performance is attributed to the higher structural activity of the Ti-doped Ca12Al14O33 crystals, characterized by lower formation and chloride embedding energies compared to those of Ca12Al14O33. These properties accelerate and enhance hydration and structural reorganization of the Ti-doped Ca12Al14O33, making them more effective in facilitating the formation of Friedel's salt, which demonstrates excellent fluoride removal performance and enables a "waste-to-waste" closed-loop strategy.

Lead-free double perovskites (DPs) are emerging as sustainable luminescent materials owing to their low-cost synthesis, low toxicity, and superior stability. However, their practical applications are impeded by low luminescence efficiency and a single emission center. To overcome these challenges, we reported a structure-modulation strategy to develop Sb/Er: Cs2Na0.95Ag0.05YbCl6 (Sb/Er: CNAYC) DPs by co-doping Cs2NaYbCl6 with Sb3+/Er3+ ions and substituting Na+ with Ag + ions. The Sb3+/Er3+ co-doping can introduce multiple emission centers from visible to near-infrared (NIR). Meanwhile, the Na+-Ag+ alloying-induced lattice distortion not only enhances the photoluminescence efficiency by breaking the parity-forbidden transitions, but also enables the color of emission to be tuned to the white light range. The Sb/Er: CNAYC DPs simultaneously deliver efficient blue (460 nm@Sb3+), green/red (552/667 nm@ Er3+) and NIR (980/1540 nm@Yb3+/Er3+) emissions, providing a promising luminescent material for single-component white/NIR LEDs. Furthermore, the Sb/Er: CNAYC DPs also display pronounced temperature-sensitive fluorescence intensity ratio (FIR) and lifetime characteristics, enabling them well-suited for dual-mode temperature sensing. This study is expected to establish a universal lattice-modulation strategy that yields single-component luminescent materials exhibiting both high-efficiency white/NIR emission and accurate multimode thermometry for next-generation optoelectronic applications.

Surface-enhanced Raman scattering (SERS) substrates with intense hot spots, superior charge transfer, and exceptional adsorption properties have garnered significant interest in ultrasensitive pesticide detection on fruits. Herein, we developed three-dimensional ZnO nanoflowers coated with ultrathin g-C3N4 layers and decorated with Ag nanoparticles (ZnO/g-C3N4/Ag) as SERS substrates. Electromagnetic simulations reveal that the ZnO/g-C3N4 nanosheets enhance electromagnetic field localization and generate abundant "hot spots". The ZnO/g-C3N4 nanosheets also provide extensive heterojunction areas and improve analyte adsorption, facilitating charge separation and transfer. These synergistic effects yield exceptional SERS performance, achieving a picomolarlevel detection limit for R6G and exceptional self-cleaning capabilities. This substrate effectively detects multiple pesticides on apple skin, with detection limits as low as a few ng/cm2. This research paves the way for developing novel 3D g-C3N4-based SERS substrates, advancing the highly sensitive detection of pesticide residues on fruits.

Two-dimensional (2D) conjugated metal-organic framework (MOF)-based heterostructures have attracted significant attention in third-order nonlinear optical (NLO) applications. However, the preparation of conjugated MOF heterostructures poses a significant challenge due to strong interlayer π-π stacking interactions. Herein, we report the fabrication of 2D porphyrin-based MOF (CuTCPP) thin films grown on graphene oxide (GO) via a liquid-phase epitaxy (LPE) layer-by-layer (LBL) method, forming a CuTCPP@GO heterostructure with strong interfacial π-π interactions. The CuTCPP@GO composite is incorporated into a polydimethylsiloxane (PDMS) matrix to produce a flexible PDMS glass for practical optical limiting (OL) application, which exhibits excellent mechanical flexibility and optical transparency while retaining the nonlinear optical functionality. The resulting CuTCPP@GO/PDMS exhibits dramatically enhanced OL performance with a nonlinear absorption coefficient of 3.3 × 10-9 m·W-1 and a lower OL threshold of 0.74 J·cm-2 than those of its individual components, attributed to the synergistic combination of extended π-conjugation and efficient interfacial charge transfer. This study provides a blueprint for the rational design of high-performance optical limiting materials through precise interfacial engineering and highlights the untapped potential of 2D MOF/graphene oxide heterostructures in nonlinear optical and optoelectronic applications.

Multifunctional electronic skin has attracted remarkable attention for its promising applications in health monitoring and human-machine interaction. However, it is still challenging to develop a multifunctional sensor via a single functional material or structure that achieves high sensitivity and multi-signal decoupling. This paper proposes a dual-mode flexible tactile sensor that generates distinct capacitive responses to both temperature and pressure stimuli. By synergy effect of hierarchical micropyramids structure and compressible PVA/MXene ionic gel electrolyte, the sensor demonstrates remarkable pressure sensitivity of 23.22 % kPa- 1 with the range of 0-133.5 kPa, temperature sensitivity of 0.975 % degrees C- 1 with the range of 25-75 degrees C. According to the capacitive response characteristics of temperature and pressure, the machine learning-enhanced multifunctional sensor can simultaneously identify and distinguish capacitance signals generated by temperature-pressure stimuli, achieving an impressive accuracy rate of 98.52 %. Finally, a 4 x 4 sensor array was printed to detect braille of six different meanings with accurate identification. Owing to the simple 'sandwich' structure design, ionic transport mechanisms, and machine learning algorithms, the sensor provides a cost-effective and promising method to multimodal signals decoupling, which paves the development of e-skin and human-computer interaction applications.

Photocatalytic oxygen reduction reaction (ORR) represents a clean and sustainable strategy for hydrogen peroxidation (H2O2) production, yet it faces challenges including charge transfer and activation of O-2. The introduced of alkali metal doping and cyano group defects into C3N4 will improve the charge carrier separation efficiency and optimize the ORR pathway, thus facilitating H2O2 production over C3N4. In this study, we prepared K-doped and cyanide-modified carbon nitride (Kx-CN) using a simple potassium salt-assisted thermal copolymerization strategy. The H2O2 formation rate of K-5-CN reached at 876.7 mu M g(-1) h(-1), about 5.5 times that of the original C3N4. Moreover, the photocatalytic ORR pathway was modulated by an external magnetic field, which further increased the H2O2 yield to 2208.2 mu M g(-1) h(-1). Meanwhile, the regulation of furfural oxidation products was achieved through the application of magnetic fields. This work highlights the significant role of the external magnetic field in exciton dissociation and ORR pathway regulation, providing a new idea for the efficient H2O2 production.

The cost-effective and scalable synthesis and patterning of soft nanomaterial composites with improved electrical conductivity and mechanical stretchability remains challenging in wearable devices. This work reports a scalable, low-cost fabrication approach to directly create and pattern crumpled porous graphene/NiS2 nanocomposites with high mechanical stretchability and electrical conductivity through laser irradiation combined with electrodeposition and a pre-strain strategy. With modulated mechanical stretchability and electrical conductivity, the crumpled graphene/NiS2 nanocomposite can be readily patterned into target geometries for application in a standalone stretchable sensing platform. By leveraging the electrical energy harvested from the kinetic motion from wearable triboelectric nanogenerator (TENG) and stored in micro-supercapacitor arrays (MSCAs) to drive biophysical sensors, the system is demonstrated to monitor human motions, body temperature, and toxic gas in the exposed environment. The material selections, design strategies, and fabrication approaches from this study provide functional nanomaterial composites with tunable properties for future high-performance bio-integrated electronics.

Highly sensitive flexible strain sensor with synergistic personal thermal management capability and electromagnetic interference (EMI) shielding holds substantial promise in integrated smart wearable electronics. Herein, a novel flexible and breathable phase change fibrous composite membrane (TPPCM) is fabricated via coaxial electrospinning technique, which is then combined with carbon nanotubes (CNTs) and MXene to develop a novel highly sensitive and physically comfortable strain sensor. It is found that the TPPCM-based strain sensor exhibits high sensitivity (GF similar to 2126.1), wide strain-detecting range (160 %), excellent durability, superior thermal energy storage/release and electro-thermal conversation properties. Typically, the encapsulation of polyethylene glycol (PEG) into TPPCM effectively overcomes the leakage problem of pristine phase change materials, and exhibits superior thermal energy management capability in both heating and cooling process. Meanwhile, the excellent conductive network endows the sensor with promising human thermal therapy function (similar to 42 degrees C) at a low applied voltage of 6 V and superior EMI shielding efficiency (>20 dB). Moreover, the porous structure endows the flexible strain sensor with good flexibility and breathability. This work proposes a new design strategy for multifunctional strain sensors from the perspective of physical comfort, which is expected to pave the way for the development of emerging physically comfortable wearable electronics.

Multifunctional optical materials with temperature sensing and anti-counterfeiting properties play an essential role in the commercial applications. Herein, Mn2+/Nd3+ co-doped Cs2AgInCl6 (CAIC) lead-free double perovskites (DPs) is synthesized through a hydrothermal method, which exhibits visible to near-infrared (NIR) luminescence and reversible photochromic properties from yellowish to dark purple. The mechanism investigations on the photoluminescence and photochromic phenomena reveal that the incorporation of Mn2+ ions not only acts as an intermediary in the energy transfer process from the host exciton to Nd3+ ions, but also plays a pivotal role in the reversible photochromic response. The temperature-dependent luminescence, attributed to the contrasting thermal responses of Mn2+ and Nd3+ ions, enables precise temperature sensing via the fluorescence intensity ratio method. In addition, the integration of visible red emission, NIR luminescence, and photochromic properties in a single CAIC: Mn2+/Nd3+ DPs, offers a multilevel anti-counterfeiting strategy. The multifunctional CAIC: Mn2+/Nd3+ DPs would open up new avenues for advanced optical applications, particularly in the realms of temperature sensing and security anti-counterfeiting.