Aggregation-induced emission-based luminogens(AIEgens)have aroused enormous interest due to their unique high fluorescence in a condensed state.To further explore their potential applications,such as chemical monitori...Aggregation-induced emission-based luminogens(AIEgens)have aroused enormous interest due to their unique high fluorescence in a condensed state.To further explore their potential applications,such as chemical monitoring,immobilization of AIE molecules has been widely studied with a variety of supports.Crystalline porous materials,such as metal-organic frameworks,covalent organic frameworks,hydrogen-bonded organic framework,and organic cages,demonstrate well-controlled structures,large surface areas,and promising stabilities,thus providing a perfect platform for AIE agents loading.Outstanding chemical sensing performances are achieved based on these AIE-active crystalline porous materials,such as high sensitivity,short response time,selective identification,and high recyclability,which provide a new alternative to readily detect various hazardous molecules.Furthermore,precise structures of AIEgen-based crystalline porous materials offer an easy way to investigate detection mechanisms.This mini-review will provide a brief overview of AIEgen-based crystalline porous materials for detection and then address how to improve sensing performances remarkably.展开更多
Molybdenum disulfide(MoS_(2))-based nanostructures are highly desirable for applications such as chemical and biological sensing,photo/electrochemical catalysis,and energy storage due to their unique physical and chem...Molybdenum disulfide(MoS_(2))-based nanostructures are highly desirable for applications such as chemical and biological sensing,photo/electrochemical catalysis,and energy storage due to their unique physical and chemical properties.In this work,MoS_(2)core-shell nanoparticles were first prepared through the liquid-phase processing of bulk MoS2by a femtosecond laser.The core of prepared nanoparticles was incompletely and weakly crystalline MoS_(2);the shell of prepared nanoparticles was highly crystalline MoS_(2),which wrapped around the core layer by layer.The femtosecond laser simultaneously achieved liquid-phase ablation and light exfoliation.The formation mechanism of the core-shell nanoparticles is to prepare the nanonuclei first by laser liquid-phase ablation and then the nanosheets by light exfoliation;the nanosheets will wrap the nanonuclei layer by layer through van der Waals forces to form core-shell nanoparticles.The MoS_(2)core-shell nanoparticles,because of Mo-S bond breakage and recombination,have high chemical activity for chemical catalysis.Afterward,the nanoparticles were used as a reducing agent to directly prepare three-dimensional(3D)Au-MoS_(2)micro/nanostructures,which were applied as surface-enhanced Raman spectroscopy(SERS)substrates to explore chemical sensing activity.The ultrahigh enhancement factor(1.06×10^(11)),ultralow detection limit(10-13M),and good SERS adaptability demonstrate highly sensitive SERS activity,great ability of ultralow concentration detection,and ability to detect diverse analytes,respectively.This work reveals the tremendous potential of 3D Au-MoS_(2)composite structures as excellent SERS substrates for chemical and biological sensing.展开更多
Single-atom catalysts(SACs)attract widespread attention in heterogeneous catalysis due to their maximum atomic utilization efficiency and unique physical and chemical properties.However,their applications in chemical ...Single-atom catalysts(SACs)attract widespread attention in heterogeneous catalysis due to their maximum atomic utilization efficiency and unique physical and chemical properties.However,their applications in chemical sensing keep huge potential but remain unclear.Herein,a Ni-N_(4)-C SAC was synthesized for the trace detection of dopamine(DA)and uric acid(UA).The Ni-N_(4)-C SAC exhibited superior sensing performance compared to the Ni clusters.The detection range for DA and UA were 0.05–75μM and 5–90μM with detection limits of 0.027 and 0.82μM,respectively.Density functional theory(DFT)computations indicate that Ni-N_(4)-C has a lower reaction barrier during electrochemical process,indicating that the atomic Ni sites possess higher intrinsic activity than Ni clusters.Moreover,DA and UA show strong potential dependency on the Ni-N_(4)-C catalyst,indicating its applicability for their concurrent detection.This work extends the application of SACs in chemical sensing.展开更多
We use distributed fiber optic strain sensing to examine swelling of the fiber’s polymer coating.The distributed sensing technique that uses unmodified low-cost telecom fibers opens a new dimension of applications th...We use distributed fiber optic strain sensing to examine swelling of the fiber’s polymer coating.The distributed sensing technique that uses unmodified low-cost telecom fibers opens a new dimension of applications that include leak detection,monitoring of water quality,and waste systems.On a short-range length scale,the technology enables“lab-on-a-fiber”applications for food processing,medicine,and biosensing for instance.The chemical sensing is realized with unmodified low-cost telecom optical fibers,namely,by using swelling in the coating material of the fiber to detect specific chemicals.Although generic and able to work in various areas such as environmental monitoring,food analysis,agriculture or security,the proposed chemical sensors can be targeted for water quality monitoring,or medical diagnostics where they present the most groundbreaking nature.Moreover,the technique is without restrictions applicable to longer range installations.展开更多
Well crystalline gadolinium oxide（Gd2O3） nanostructures were grown by annealing the hydrothermally as-prepared nanostructures without using any template. Microscopic studies of Gd2O3 nanostructures were recorded alo...Well crystalline gadolinium oxide（Gd2O3） nanostructures were grown by annealing the hydrothermally as-prepared nanostructures without using any template. Microscopic studies of Gd2O3 nanostructures were recorded along the [111] direction due to the clearly resolved interplanar distance d（222）-0.31 nm of the cubic crystal structure Gd2O3. Sensing mechanism of Gd2O3 as efficient electron mediator for the detection of ethanol was explored. As-fabricated sensor demonstrated the high-sensitivity of -0.266 μAm/M/cm2 with low detection limit（-52.2 μmol/L） and correlation coefficient（r^2, 0.618）. To the best of our knowledge, this was the first report for the detection of ethanol using as-grown（at 1000 oC） Gd2O3 nanostructures by simple and reliable Ⅰ-Ⅴ technique and rapid assessment of the reaction kinetics（in the order of seconds）. The low cost of the starting reagents and the simplicity of the synthetic route made it a promising chemical sensor for the detection of various toxic analytes, which are not environmentally safe.展开更多
Black phosphorus （BP）, an attractive two-dimensional （2D） semiconductor, is widely used in the fields of optoelec- tronic devices, biomedicine, and chemical sensing. Silver ion （Ag＋）, a commonly used additive i...Black phosphorus （BP）, an attractive two-dimensional （2D） semiconductor, is widely used in the fields of optoelec- tronic devices, biomedicine, and chemical sensing. Silver ion （Ag＋）, a commonly used additive in food industry, can sterilize and keep food fresh. But excessive intake of Ag＋ will harm human health. Therefore, high sensitive, fast and simple Ag＋ detection method is significant. Here, a high-performance BP field effect transistor （FET） sensor is fabricated for Ag＋ detection with high sensitivity, rapid detection speed, and wide detection concentration range. The detection limit for Ag＋ is 10 l0 mol/L. Testing time for each sample by this method is 60 s. Besides, the mechanism of BP-FET sensor for Ag＋ detection is investigated systematically. The simple BP-FET sensor may inspire some relevant research and potential applications, such as providing an effective method for the actual detection of Ag＋, especially in wimessed inspections field of food.展开更多
Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX) is one of the most widely used powerful explosives. The direct and selective detection of HMX, without the requirement of specialized equipment, remains a great ch...Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX) is one of the most widely used powerful explosives. The direct and selective detection of HMX, without the requirement of specialized equipment, remains a great challenge due to its extremely low volatility, unfavorable reduction potential and lack of aromatic rings. Here, we report the first chemical probe of direct identification of HMX at ppb sensitivity based on a designed metal-organic cage(MOC). The cage features two unsaturated dicopper units and four electron donating amino groups inside the cavity, providing multiple binding sites to selectively enhance host-vip events. It was found that compared to other explosive molecules the capture of HMX inside the cavity would strongly modulate the emissive behavior of the host cage, resulting in highly induced fluorescence “turn-on”(160 folds). Based on the density functional theory(DFT) simulation, the mutual fit of both size and binding sites between host and vip leads to the synergistic effects that perturb the ligand-to-metal charge-transfer(LMCT) process, which is probably the origin of such selective HMX-induced turn-on behavior.展开更多
In-situ monitoring of pesticide residues during crop growth or/and in related products is of great significance in avoiding the abuse of pesticides but remains challenging thus far.In this report,we proposed a backgro...In-situ monitoring of pesticide residues during crop growth or/and in related products is of great significance in avoiding the abuse of pesticides but remains challenging thus far.In this report,we proposed a background-free surface-enhanced Raman spectroscopy(bf-SERS)platform to non-destructively track the nitrile-bearing pesticide residues in soybean leaves with high sensitivity and selectivity.The outstanding feature of the assay stems from the dramatic Raman enhancement effect of the 50 nm-sized gold nanoparticles(AuNPs)towards the pesticides and simultaneously the background-free Raman signal of the nitrile group in the so-called Raman-silent region(1800-2800 cm^(-1)).This bf-SERS assay was applied to evaluate the penetration effects of nitrile-bearing pesticides and monitor their residues in soybean leaves after rinsing with various solutions,providing a reliable tool for guiding the safe use of nitrile-bearing pesticides in agriculture.展开更多
Chemical and biological sensing play important roles in healthcare,environmental science,food-safety tests,and medical applications.Flexible organic electrochemical transistors(OECTs)have shown great promise in the fi...Chemical and biological sensing play important roles in healthcare,environmental science,food-safety tests,and medical applications.Flexible organic electrochemical transistors(OECTs)have shown great promise in the field of chemical and biological sensing,owing to their superior sensitivity,high biocompatibility,low cost,and light weight.Herein,we summarize recent progress in the fabrication of flexible OECTs and their applications in chemical and biological sensing.We start with a brief introduction to the working principle,configuration,and sensing mechanism of the flexible OECT-based sensors.Then,we focus on the fabrication of flexible OECT-based sensors,including material selection and structural engineering of the components in OECTs:the substrate,electrodes,electrolyte,and channel.Particularly,the gate modification is discussed extensively.Then,the applications of OECT-based sensors in chemical and biological sensing are reviewed in detail.Especially,the array-based and integrated OECT sensors are also introduced.Finally,we present the conclusions and remaining challenges in the field of flexible OECT-based sensing.Our timely review will deepen the understanding of the flexible OECT-based sensors and promote the further development of the fast-growing field of flexible sensing.展开更多
To approach basic scientific questions on the origin and evolution of plan- etary bodies such as planets, their satellites and asteroids, one needs data on their chemical composition. The measurements of gamma-rays, X...To approach basic scientific questions on the origin and evolution of plan- etary bodies such as planets, their satellites and asteroids, one needs data on their chemical composition. The measurements of gamma-rays, X-rays and neutrons emit- ted from their surface materials provide information on abundances of major elements and naturally radioactive gamma-ray emitters. Neutron spectroscopy can provide sen- sitive maps of hydrogen- and carbon-containing compounds, even if buried, and can uniquely identify layers of carbon-dioxide frost. Nuclear spectroscopy, as a means of compositional analysis, has been applied via orbital and lander spacecraft to extrater- restrial planetary bodies： the Moon, Venus, Mars, Mercury and asteroids. The knowl- edge of their chemical abundances, especially concerning the Moon and Mars, has greatly increased in recent years. This paper describes the principle of nuclear spec- troscopy, nuclear planetary instruments carried on planetary missions so far, and the nature of observational results and findings of the Moon and Mars, recently obtained by nuclear spectroscopy.展开更多
Simple, portable analytical devices are entering our daily lives for personal care, clinical analysis, allergen detection in food, and environmental monitoring. Smart- phones, as the most popular state-of-art mobile d...Simple, portable analytical devices are entering our daily lives for personal care, clinical analysis, allergen detection in food, and environmental monitoring. Smart- phones, as the most popular state-of-art mobile device, have remarkable potential for sensing applications. A growing set of physical-co-chemical sensors have been embedded; these include accelerometers, microphones, cameras, gyroscopes, and GPS units to access and perform data analysis. In this review, we discuss recent work focusing on smartphone sensing including representative electromag- netic, audio frequency, optical, and electrochemical sen- sors. The development of these capabilities will lead to more compact, lightweight, cost-effective, flexible, and durable devices in terms of their performances.展开更多
Metal-organic frameworks(MOFs)exhibit attractive properties such as highly accessible surface area,large porosity,tunable pore size,and built-in redox-active metal sites.They may serve as excellent candidates to const...Metal-organic frameworks(MOFs)exhibit attractive properties such as highly accessible surface area,large porosity,tunable pore size,and built-in redox-active metal sites.They may serve as excellent candidates to construct implantable flexible devices for biochemical sensing due to their high thermal and solution stability.However,MOFs-based sensors have only been mostly reported for in-vitro chemical sensing,their use in implantable chemical sensing and combination with flexible electronics to achieve excellent mechanical compatibility with tissues and organs has rarely been summarized.This paper systematically reviews the biochemical sensors based on MOFs and discusses the feasibility to achieve implantable biochemical sensing through MOFs-based flexible electronics.The properties of MOFs and underlying mechanisms have been intrcxluced,followed by a summarization of different biochemical sensing applications.Strategies to integrate MOFs with flexible devices have been supplied from the standpoints of matching mechanics and compatible fabrication processes.Issues that should be addressed in developing flexible MOFs sensors and potential solutions have also been provided,followed by the perspective for future applications of flexible MOFs sensors.This paper may serve as a reference to offer potential guidelines for the development of flexible MOFs-based biochemical sensors that may benefit future applications in personal healthcare,disease diagnosis and treatment,and fundamental study of various biological processes.展开更多
Modern internet of things(IoTs)and ubiquitous sensor networks could potentially take advantage of chemically sensitive nanomaterials and nanostructures.However,their heterogeneous integration with other electronic mod...Modern internet of things(IoTs)and ubiquitous sensor networks could potentially take advantage of chemically sensitive nanomaterials and nanostructures.However,their heterogeneous integration with other electronic modules on a networked sensor node,such as silicon-based modulators and memories,is inherently challenging because of compatibility and integration issues.Here we report a novel paradigm for sensing modulators:a graphene field-effect transistor device that directly modulates a radio frequency(RF)electrical carrier signal when exposed to chemical agents,with a memory effect in its electrochemical history.We demonstrated the concept and implementation of this graphene-based sensing modulator through a frequency-modulation(FM)experiment conducted in a modulation cycle consisting of alternating phases of air exposure and ethanol or water treatment.In addition,we observed an analog memory effect in terms of the charge neutrality point of the graphene,Vcnp,which strongly influences the FM results,and developed a calibration method using electrochemical gate-voltage pulse sequences.This graphenebased multifunctional device shows great potential for use in a simple,low-cost,and ultracompact nanomaterial-based nodal architecture to enable continuous,real-time event-based monitoring in pervasive healthcare IoTs,ubiquitous security systems,and other chemical/molecular/gas monitoring applications.展开更多
Capacitive Micromachined Ultrasonic Transducer(CMUT)are widely utilized in fields such as medical imaging,nondestructive testing,and chemical sensing for active sensing applications.However,the capacitive structure of...Capacitive Micromachined Ultrasonic Transducer(CMUT)are widely utilized in fields such as medical imaging,nondestructive testing,and chemical sensing for active sensing applications.However,the capacitive structure of CMUT also demonstrates significant potential in the domain of passive pressure sensing.This study is the first to apply the CMUT structure to passive pressure sensing in high hydrostatic pressure environments.The CMUT pressure sensor,fabricated using MEMS technology,demonstrates high consistency,with a maximum static capacitance deviation of only 1%among multiple sensors.Experimental results from high hydrostatic pressure testing indicate that the sensor can reliably measure pressures exceeding 20 MPa with real-time responsiveness.After being placed in a dynamic pressure chamber for three months,the sensor’s pressure measurements remained consistent with the initial results,exhibiting a maximum deviation of just 0.65%,demonstrating excellent repeatability.These experiments confirm the high reliability and outstanding long-term stability of the sensor,laying a foundation for CMUT structure applications in high hydrostatic pressure sensing.展开更多
Terahertz(THz)microscopy has attracted attention owing to distinctive characteristics of the THz frequency region,particularly non-ionizing photon energy,spectral fingerprint,and transparency to most nonpolar material...Terahertz(THz)microscopy has attracted attention owing to distinctive characteristics of the THz frequency region,particularly non-ionizing photon energy,spectral fingerprint,and transparency to most nonpolar materials.Nevertheless,the well-known Rayleigh diffraction limit imposed on THz waves commonly constrains the resultant imaging resolution to values beyond the millimeter scale,consequently limiting the applicability in numerous emerging applications for chemical sensing and complex media imaging.In this theoretical and numerical work,we address this challenge by introducing,to our knowledge,a new imaging approach based on acquiring high-spatial frequencies by adapting the Fourier synthetic aperture approach to the THz spectral range,thus surpassing the diffractionlimited resolution.Our methodology combines multi-angle THz pulsed illumination with time-resolved field measurements,as enabled by the state-of-the-art time-domain spectroscopy technique.We demonstrate the potential of the approach for hyperspectral THz imaging of semi-transparent samples and show that the technique can reconstruct spatial and temporal features of complex inhomogeneous samples with subwavelength resolution.展开更多
CONSPECTUS:Covalent organic frameworks(COFs)are a rapidly evolving class of crystalline porous materials with customizable topologies,tunable functionalities,and a broad scope of applications ranging from catalysis to...CONSPECTUS:Covalent organic frameworks(COFs)are a rapidly evolving class of crystalline porous materials with customizable topologies,tunable functionalities,and a broad scope of applications ranging from catalysis to optoelectronics.Despite substantial progress in framework design,the controlled growth of single-crystalline COFs remains a formidable challenge due to the relatively poor reversibility of covalent bond formation and the difficulty in modulating nucleation and growth kinetics.Traditional solvothermal strategies often yield polycrystalline powders and require prolonged reaction times,limiting access to defect-free structures essential for in-depth structural characterization and advanced functional applications.In this Account,we present the supercritical solvothermal method as a transformative strategy that simultaneously achieves ultrarapid synthesis and high crystallinity of COFs.By leveraging the unique physicochemical properties of supercritical carbon dioxide(sc-CO_(2)),notably its low viscosity,high diffusivity,and tunable solvent density,this method overcomes the trade-off between synthesis duration and crystal quality.This approach enables the synthesis of single-crystalline COFs in a few minutes,compared to hours or days in conventional systems.Mechanistically,sc-CO_(2) facilitates dynamic mass transport and enhanced molecular mobility,which accelerate nucleation while promoting defect self-healing during framework propagation.Time-resolved characterization combined with template infiltration experiments reveals that the exceptional penetrability of sc-CO_(2) enables framework formation even within confined micropores and allows for precise morphological tuning of COFs.Furthermore,we demonstrate that weak intermolecular forces such as interlayer electrostatic repulsions and hydrogen bonding can be amplified under supercritical fluid conditions to modulate crystal morphology,leading to the formation of rare helical COF crystals and enabling structure manipulation via rational side-group engineering.Single-crystalline COFs exhibit specific properties and potential applications,particularly in nonlinear optics,optoelectronics,and chemical sensing.These crystals display high second harmonic generation efficiencies due to their noncentrosymmetric packing,as well as robust third-order nonlinear responses enabled by chromophore alignment andπ-electron delocalization.In optoelectronic applications,dual-state COF phototransistors demonstrate room-temperature responsivity of∼4.6×1010 A·W−1 and detectivity of 1.62×1016 Jones,enabling high-contrast neuromorphic imaging under low-light and aqueous conditions.In chemical sensing applications,COF/graphene heterostructures synthesized via this method deliver unprecedented detection limits,down to 10−19 M for methylglyoxal and 10−10 M for mercury ions in biofluids,by integrating photochemical gating effects and exploiting ordered charge-transfer interfaces.Overall,this Account establishes the supercritical solvothermal method as a general and scalable platform for single-crystal COF synthesis.It not only broadens the synthetic scope to previously inaccessible topologies and linkage chemistries but also paves the way for the integration of COFs into high-performance photonic,electronic,and biomedical devices.Future opportunities lie in tuning fluid dynamics for dimensionality control,coupling with nucleation or competitive reaction strategies to access new architectures,and extending the kinetic framework to guide crystallization in other polymeric and supramolecular materials.展开更多
Detecting trace pesticide residues in food products is crucial for ensuring food safety.Terahertz technology has demonstrated significant advantages in chemical and biological sensing by utilizing the vibrational sign...Detecting trace pesticide residues in food products is crucial for ensuring food safety.Terahertz technology has demonstrated significant advantages in chemical and biological sensing by utilizing the vibrational signatures inherent to molecules in the terahertz spectrum and leveraging the amplified electric fields facilitated by metamaterials.In this work,we introduce a novel method for imidacloprid(IMI)pesticide residue detection using the rod-shaped terahertz metamaterial(RSTM)with a composite interface of gold and conductive polymer polyaniline(PANI).The core mechanism of this method relies on the binding of IMI to PANI,which alters the resonance intensity and frequency of the Au-PANI-RSTM.Specifically,the RSTM parameters are determined using computer simulation technology(CST),and the RSTM structure is engraved on the Au-PANI surface using laser direct writing technology.Further characterization using mid-infrared spectroscopy(MIR)and X-ray photoelectron spectroscopy(XPS)techniques reveals that the stable bonding between PANI and IMI is facilitated by hydrogen bonding and covalent bonding.The detection limit of Au-PANI-RSTM deposited with 20 segments for IMI is 0.46 ppm,which complies with the maximum residue limit for IMI stipulated in the Chinese National Standard.展开更多
This paper reports a complete micro gas chromatography(μGC)system in which all the components are lithographically microfabricated and electronically interfaced.The components include a bi-directional Knudsen pump,a ...This paper reports a complete micro gas chromatography(μGC)system in which all the components are lithographically microfabricated and electronically interfaced.The components include a bi-directional Knudsen pump,a preconcentrator,separation columns and a pair of capacitive gas detectors;together,these form the iGC3.c2 system.All the fluidic components of the system are fabricated by a common three-mask lithographic process.The Knudsen pump is a thermomolecular pump that provides air flow to theμGC without any moving parts.The film heaters embedded in the separation columns permit temperature programming.The capacitive detectors provide complementary response patterns,enhancing vapor recognition and resolving coeluting peaks.With the components assembled on printed circuit boards,the system has a footprint of 8×10 cm^(2).Using room air as the carrier gas,the system is used to experimentally demonstrate the analysis of 19 chemicals with concentration levels on the order of parts per million(p.p.m.)and parts per billion(p.p.b.).The tested chemicals include alkanes,aromatic hydrocarbons,aldehydes,halogenated hydrocarbons and terpenes.This set of chemicals represents a variety of common indoor air pollutants,among which benzene,toluene and xylenes(BTX)are of particular interest.展开更多
The engineered biomimetic sensors can not only realize the action of organs,but also combine functional materials as in vitro organs by simulating the response of biological organs to different environmental signals.A...The engineered biomimetic sensors can not only realize the action of organs,but also combine functional materials as in vitro organs by simulating the response of biological organs to different environmental signals.Artificial nose is a concept proposed by imitating biological olfactory system,simulating olfactory nerve cells,olfactory bulb and olfactory cortex through different materials to realize olfactory function.The sensor array used to sense external gas stimulation can be analyzed based on different recognition principles through different original signals such as optics,electricity,electrochemistry and bioelectricity.Furthermore,combined with pattern recognition and microarray technology,artificial nose can be highly integrated with biocompatible and other important properties to achieve in vitro application.The design principle and necessary components of artificial nose are introduced in this paper including sensing structure,recognition system and functional module.At the same time,the potential development prospects of molecular recognition technology,polymer-based materials and microarray integration in artificial nose are prospected.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:21571079,21621001,21390394,21571076,21571078″111″project,Grant/Award Numbers:B07016,B17020JLU Science and Technology Innovative Research Team。
文摘Aggregation-induced emission-based luminogens(AIEgens)have aroused enormous interest due to their unique high fluorescence in a condensed state.To further explore their potential applications,such as chemical monitoring,immobilization of AIE molecules has been widely studied with a variety of supports.Crystalline porous materials,such as metal-organic frameworks,covalent organic frameworks,hydrogen-bonded organic framework,and organic cages,demonstrate well-controlled structures,large surface areas,and promising stabilities,thus providing a perfect platform for AIE agents loading.Outstanding chemical sensing performances are achieved based on these AIE-active crystalline porous materials,such as high sensitivity,short response time,selective identification,and high recyclability,which provide a new alternative to readily detect various hazardous molecules.Furthermore,precise structures of AIEgen-based crystalline porous materials offer an easy way to investigate detection mechanisms.This mini-review will provide a brief overview of AIEgen-based crystalline porous materials for detection and then address how to improve sensing performances remarkably.
基金supported by the National Natural Science Foundation of China(Grant Nos.52105427,U2037205,52005041,51575053,and 51775047)Research Foundation from Ministry of Education of China(Grant No.6141A02033123)+2 种基金Beijing Municipal Commission of Education(Grant No.KM201910005003)Knowledge Innovation Program of Wuhan-Basic Research(Grant No.2022010801010349)Scientific Research Project of Hubei Provincial Department of Education(Grant No.B2022055)。
文摘Molybdenum disulfide(MoS_(2))-based nanostructures are highly desirable for applications such as chemical and biological sensing,photo/electrochemical catalysis,and energy storage due to their unique physical and chemical properties.In this work,MoS_(2)core-shell nanoparticles were first prepared through the liquid-phase processing of bulk MoS2by a femtosecond laser.The core of prepared nanoparticles was incompletely and weakly crystalline MoS_(2);the shell of prepared nanoparticles was highly crystalline MoS_(2),which wrapped around the core layer by layer.The femtosecond laser simultaneously achieved liquid-phase ablation and light exfoliation.The formation mechanism of the core-shell nanoparticles is to prepare the nanonuclei first by laser liquid-phase ablation and then the nanosheets by light exfoliation;the nanosheets will wrap the nanonuclei layer by layer through van der Waals forces to form core-shell nanoparticles.The MoS_(2)core-shell nanoparticles,because of Mo-S bond breakage and recombination,have high chemical activity for chemical catalysis.Afterward,the nanoparticles were used as a reducing agent to directly prepare three-dimensional(3D)Au-MoS_(2)micro/nanostructures,which were applied as surface-enhanced Raman spectroscopy(SERS)substrates to explore chemical sensing activity.The ultrahigh enhancement factor(1.06×10^(11)),ultralow detection limit(10-13M),and good SERS adaptability demonstrate highly sensitive SERS activity,great ability of ultralow concentration detection,and ability to detect diverse analytes,respectively.This work reveals the tremendous potential of 3D Au-MoS_(2)composite structures as excellent SERS substrates for chemical and biological sensing.
基金supported by the National Key R&D Program of China(Nos.2022YFA1505100 and 2022YFB4102000)the National Natural Science Foundation of China(Nos.52105145,12274124,and 22002088)+2 种基金the Shanghai Pilot Program for Basic Research(No.22TQ1400100-6)the Fundamental Research Funds for the Central Universitiessupported by Key Laboratory of Theoretical and Computational Photochemistry,Ministry of Education,College of Chemistry,Beijing Normal University。
文摘Single-atom catalysts(SACs)attract widespread attention in heterogeneous catalysis due to their maximum atomic utilization efficiency and unique physical and chemical properties.However,their applications in chemical sensing keep huge potential but remain unclear.Herein,a Ni-N_(4)-C SAC was synthesized for the trace detection of dopamine(DA)and uric acid(UA).The Ni-N_(4)-C SAC exhibited superior sensing performance compared to the Ni clusters.The detection range for DA and UA were 0.05–75μM and 5–90μM with detection limits of 0.027 and 0.82μM,respectively.Density functional theory(DFT)computations indicate that Ni-N_(4)-C has a lower reaction barrier during electrochemical process,indicating that the atomic Ni sites possess higher intrinsic activity than Ni clusters.Moreover,DA and UA show strong potential dependency on the Ni-N_(4)-C catalyst,indicating its applicability for their concurrent detection.This work extends the application of SACs in chemical sensing.
基金We would like to thank Sina Sedighi and Prof.Marcelo Soto for fruitful discussions and for help with signal processing.This work was financed by the Romanian Ministry of Education and Research(Grant No.34/01.09.2016,ID:P_37_788,MySMIS:103364),project co-funded by the European Regional Development Fund through the Competitiveness Operational Program.
文摘We use distributed fiber optic strain sensing to examine swelling of the fiber’s polymer coating.The distributed sensing technique that uses unmodified low-cost telecom fibers opens a new dimension of applications that include leak detection,monitoring of water quality,and waste systems.On a short-range length scale,the technology enables“lab-on-a-fiber”applications for food processing,medicine,and biosensing for instance.The chemical sensing is realized with unmodified low-cost telecom optical fibers,namely,by using swelling in the coating material of the fiber to detect specific chemicals.Although generic and able to work in various areas such as environmental monitoring,food analysis,agriculture or security,the proposed chemical sensors can be targeted for water quality monitoring,or medical diagnostics where they present the most groundbreaking nature.Moreover,the technique is without restrictions applicable to longer range installations.
基金the support of the Ministry of Higher Education, Saudi Arabia, for this research under the grant funded to promising Centre for Sensors and Electronic Devices (PCSED) at Najran University, Saudi Arabia
文摘Well crystalline gadolinium oxide（Gd2O3） nanostructures were grown by annealing the hydrothermally as-prepared nanostructures without using any template. Microscopic studies of Gd2O3 nanostructures were recorded along the [111] direction due to the clearly resolved interplanar distance d（222）-0.31 nm of the cubic crystal structure Gd2O3. Sensing mechanism of Gd2O3 as efficient electron mediator for the detection of ethanol was explored. As-fabricated sensor demonstrated the high-sensitivity of -0.266 μAm/M/cm2 with low detection limit（-52.2 μmol/L） and correlation coefficient（r^2, 0.618）. To the best of our knowledge, this was the first report for the detection of ethanol using as-grown（at 1000 oC） Gd2O3 nanostructures by simple and reliable Ⅰ-Ⅴ technique and rapid assessment of the reaction kinetics（in the order of seconds）. The low cost of the starting reagents and the simplicity of the synthetic route made it a promising chemical sensor for the detection of various toxic analytes, which are not environmentally safe.
基金Project support by the National Natural Science Foundation of China(Grant Nos.61605131 and 61435010)the Shenzhen Science and Technology Research Fund,China(Grant No.JCYJ20150324141711624)
文摘Black phosphorus （BP）, an attractive two-dimensional （2D） semiconductor, is widely used in the fields of optoelec- tronic devices, biomedicine, and chemical sensing. Silver ion （Ag＋）, a commonly used additive in food industry, can sterilize and keep food fresh. But excessive intake of Ag＋ will harm human health. Therefore, high sensitive, fast and simple Ag＋ detection method is significant. Here, a high-performance BP field effect transistor （FET） sensor is fabricated for Ag＋ detection with high sensitivity, rapid detection speed, and wide detection concentration range. The detection limit for Ag＋ is 10 l0 mol/L. Testing time for each sample by this method is 60 s. Besides, the mechanism of BP-FET sensor for Ag＋ detection is investigated systematically. The simple BP-FET sensor may inspire some relevant research and potential applications, such as providing an effective method for the actual detection of Ag＋, especially in wimessed inspections field of food.
基金the National Natural Science Foundation of China (NSFC, Nos. 21773135, 22032003, 21821001)the Ministry of Science and Technology (MOST, No. 2017YFA0204501)the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, No. TRR61)。
文摘Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX) is one of the most widely used powerful explosives. The direct and selective detection of HMX, without the requirement of specialized equipment, remains a great challenge due to its extremely low volatility, unfavorable reduction potential and lack of aromatic rings. Here, we report the first chemical probe of direct identification of HMX at ppb sensitivity based on a designed metal-organic cage(MOC). The cage features two unsaturated dicopper units and four electron donating amino groups inside the cavity, providing multiple binding sites to selectively enhance host-vip events. It was found that compared to other explosive molecules the capture of HMX inside the cavity would strongly modulate the emissive behavior of the host cage, resulting in highly induced fluorescence “turn-on”(160 folds). Based on the density functional theory(DFT) simulation, the mutual fit of both size and binding sites between host and vip leads to the synergistic effects that perturb the ligand-to-metal charge-transfer(LMCT) process, which is probably the origin of such selective HMX-induced turn-on behavior.
基金the support from the Shanxi Province Key R&D Plans(Nos.201903D211006-1 and 201803D221020-2)the Natural Science Foundation of Shanxi Province(No.201901D111225)+1 种基金the National Natural Science Foundation of China(Nos.21775075 and 21977053)the Fundamental Research Funds for the Central Universities,Nankai University(No.2122018165)。
文摘In-situ monitoring of pesticide residues during crop growth or/and in related products is of great significance in avoiding the abuse of pesticides but remains challenging thus far.In this report,we proposed a background-free surface-enhanced Raman spectroscopy(bf-SERS)platform to non-destructively track the nitrile-bearing pesticide residues in soybean leaves with high sensitivity and selectivity.The outstanding feature of the assay stems from the dramatic Raman enhancement effect of the 50 nm-sized gold nanoparticles(AuNPs)towards the pesticides and simultaneously the background-free Raman signal of the nitrile group in the so-called Raman-silent region(1800-2800 cm^(-1)).This bf-SERS assay was applied to evaluate the penetration effects of nitrile-bearing pesticides and monitor their residues in soybean leaves after rinsing with various solutions,providing a reliable tool for guiding the safe use of nitrile-bearing pesticides in agriculture.
基金the National Key R&D Program of China(No.2017YFA0204700)the National Natural Science Foundation of China(No.11974180)+2 种基金the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z-021)the China-Sweden Joint Mobility Project(No.51811530018)the Fundamental Research Funds for the Central Universities.
文摘Chemical and biological sensing play important roles in healthcare,environmental science,food-safety tests,and medical applications.Flexible organic electrochemical transistors(OECTs)have shown great promise in the field of chemical and biological sensing,owing to their superior sensitivity,high biocompatibility,low cost,and light weight.Herein,we summarize recent progress in the fabrication of flexible OECTs and their applications in chemical and biological sensing.We start with a brief introduction to the working principle,configuration,and sensing mechanism of the flexible OECT-based sensors.Then,we focus on the fabrication of flexible OECT-based sensors,including material selection and structural engineering of the components in OECTs:the substrate,electrodes,electrolyte,and channel.Particularly,the gate modification is discussed extensively.Then,the applications of OECT-based sensors in chemical and biological sensing are reviewed in detail.Especially,the array-based and integrated OECT sensors are also introduced.Finally,we present the conclusions and remaining challenges in the field of flexible OECT-based sensing.Our timely review will deepen the understanding of the flexible OECT-based sensors and promote the further development of the fast-growing field of flexible sensing.
基金supported by the Korea-Japan International Cooperative Research Program funded by the Korean Research Fund (F01-2009-000-100540-0, 10-6303)KIGAM’s Internal Project (12-3612) funded by the Ministry of Knowledge Economy
文摘To approach basic scientific questions on the origin and evolution of plan- etary bodies such as planets, their satellites and asteroids, one needs data on their chemical composition. The measurements of gamma-rays, X-rays and neutrons emit- ted from their surface materials provide information on abundances of major elements and naturally radioactive gamma-ray emitters. Neutron spectroscopy can provide sen- sitive maps of hydrogen- and carbon-containing compounds, even if buried, and can uniquely identify layers of carbon-dioxide frost. Nuclear spectroscopy, as a means of compositional analysis, has been applied via orbital and lander spacecraft to extrater- restrial planetary bodies： the Moon, Venus, Mars, Mercury and asteroids. The knowl- edge of their chemical abundances, especially concerning the Moon and Mars, has greatly increased in recent years. This paper describes the principle of nuclear spec- troscopy, nuclear planetary instruments carried on planetary missions so far, and the nature of observational results and findings of the Moon and Mars, recently obtained by nuclear spectroscopy.
文摘Simple, portable analytical devices are entering our daily lives for personal care, clinical analysis, allergen detection in food, and environmental monitoring. Smart- phones, as the most popular state-of-art mobile device, have remarkable potential for sensing applications. A growing set of physical-co-chemical sensors have been embedded; these include accelerometers, microphones, cameras, gyroscopes, and GPS units to access and perform data analysis. In this review, we discuss recent work focusing on smartphone sensing including representative electromag- netic, audio frequency, optical, and electrochemical sen- sors. The development of these capabilities will lead to more compact, lightweight, cost-effective, flexible, and durable devices in terms of their performances.
基金supported by the Key Research and Development Project of Zhejiang province(No.2021C05005).
文摘Metal-organic frameworks(MOFs)exhibit attractive properties such as highly accessible surface area,large porosity,tunable pore size,and built-in redox-active metal sites.They may serve as excellent candidates to construct implantable flexible devices for biochemical sensing due to their high thermal and solution stability.However,MOFs-based sensors have only been mostly reported for in-vitro chemical sensing,their use in implantable chemical sensing and combination with flexible electronics to achieve excellent mechanical compatibility with tissues and organs has rarely been summarized.This paper systematically reviews the biochemical sensors based on MOFs and discusses the feasibility to achieve implantable biochemical sensing through MOFs-based flexible electronics.The properties of MOFs and underlying mechanisms have been intrcxluced,followed by a summarization of different biochemical sensing applications.Strategies to integrate MOFs with flexible devices have been supplied from the standpoints of matching mechanics and compatible fabrication processes.Issues that should be addressed in developing flexible MOFs sensors and potential solutions have also been provided,followed by the perspective for future applications of flexible MOFs sensors.This paper may serve as a reference to offer potential guidelines for the development of flexible MOFs-based biochemical sensors that may benefit future applications in personal healthcare,disease diagnosis and treatment,and fundamental study of various biological processes.
基金This work was supported in part by the NSF CAREER award(D.A.),the NSF-NASCENT Engineering Research Center(Cooperative Agreement No.EEC-1160494)the Southwest Academy of Nanoelectronics(SWAN).
文摘Modern internet of things(IoTs)and ubiquitous sensor networks could potentially take advantage of chemically sensitive nanomaterials and nanostructures.However,their heterogeneous integration with other electronic modules on a networked sensor node,such as silicon-based modulators and memories,is inherently challenging because of compatibility and integration issues.Here we report a novel paradigm for sensing modulators:a graphene field-effect transistor device that directly modulates a radio frequency(RF)electrical carrier signal when exposed to chemical agents,with a memory effect in its electrochemical history.We demonstrated the concept and implementation of this graphene-based sensing modulator through a frequency-modulation(FM)experiment conducted in a modulation cycle consisting of alternating phases of air exposure and ethanol or water treatment.In addition,we observed an analog memory effect in terms of the charge neutrality point of the graphene,Vcnp,which strongly influences the FM results,and developed a calibration method using electrochemical gate-voltage pulse sequences.This graphenebased multifunctional device shows great potential for use in a simple,low-cost,and ultracompact nanomaterial-based nodal architecture to enable continuous,real-time event-based monitoring in pervasive healthcare IoTs,ubiquitous security systems,and other chemical/molecular/gas monitoring applications.
基金funded by National Key Research and Development Program(2024YFF0510000)National Natural Science Foundation of China(Grant 62522125,U23A20362,62320106011,52275578)Baiyi Program of Shanxi Province.
文摘Capacitive Micromachined Ultrasonic Transducer(CMUT)are widely utilized in fields such as medical imaging,nondestructive testing,and chemical sensing for active sensing applications.However,the capacitive structure of CMUT also demonstrates significant potential in the domain of passive pressure sensing.This study is the first to apply the CMUT structure to passive pressure sensing in high hydrostatic pressure environments.The CMUT pressure sensor,fabricated using MEMS technology,demonstrates high consistency,with a maximum static capacitance deviation of only 1%among multiple sensors.Experimental results from high hydrostatic pressure testing indicate that the sensor can reliably measure pressures exceeding 20 MPa with real-time responsiveness.After being placed in a dynamic pressure chamber for three months,the sensor’s pressure measurements remained consistent with the initial results,exhibiting a maximum deviation of just 0.65%,demonstrating excellent repeatability.These experiments confirm the high reliability and outstanding long-term stability of the sensor,laying a foundation for CMUT structure applications in high hydrostatic pressure sensing.
基金Agence Nationale de la Recherche(ANR-22-CE42-0005-HYPSTER,ANR 22-PEEL-0003-Comptera)。
文摘Terahertz(THz)microscopy has attracted attention owing to distinctive characteristics of the THz frequency region,particularly non-ionizing photon energy,spectral fingerprint,and transparency to most nonpolar materials.Nevertheless,the well-known Rayleigh diffraction limit imposed on THz waves commonly constrains the resultant imaging resolution to values beyond the millimeter scale,consequently limiting the applicability in numerous emerging applications for chemical sensing and complex media imaging.In this theoretical and numerical work,we address this challenge by introducing,to our knowledge,a new imaging approach based on acquiring high-spatial frequencies by adapting the Fourier synthetic aperture approach to the THz spectral range,thus surpassing the diffractionlimited resolution.Our methodology combines multi-angle THz pulsed illumination with time-resolved field measurements,as enabled by the state-of-the-art time-domain spectroscopy technique.We demonstrate the potential of the approach for hyperspectral THz imaging of semi-transparent samples and show that the technique can reconstruct spatial and temporal features of complex inhomogeneous samples with subwavelength resolution.
基金supported by National Science Foundation for Distinguished Young Scholars of China(T2425006)Shanghai Science and Technology Innovation Action Project(24CL2901100)+1 种基金Program of Shanghai Academic Research Leaders(23XD1420200)Wuhan Textile University Startup Fund,and Fudan University。
文摘CONSPECTUS:Covalent organic frameworks(COFs)are a rapidly evolving class of crystalline porous materials with customizable topologies,tunable functionalities,and a broad scope of applications ranging from catalysis to optoelectronics.Despite substantial progress in framework design,the controlled growth of single-crystalline COFs remains a formidable challenge due to the relatively poor reversibility of covalent bond formation and the difficulty in modulating nucleation and growth kinetics.Traditional solvothermal strategies often yield polycrystalline powders and require prolonged reaction times,limiting access to defect-free structures essential for in-depth structural characterization and advanced functional applications.In this Account,we present the supercritical solvothermal method as a transformative strategy that simultaneously achieves ultrarapid synthesis and high crystallinity of COFs.By leveraging the unique physicochemical properties of supercritical carbon dioxide(sc-CO_(2)),notably its low viscosity,high diffusivity,and tunable solvent density,this method overcomes the trade-off between synthesis duration and crystal quality.This approach enables the synthesis of single-crystalline COFs in a few minutes,compared to hours or days in conventional systems.Mechanistically,sc-CO_(2) facilitates dynamic mass transport and enhanced molecular mobility,which accelerate nucleation while promoting defect self-healing during framework propagation.Time-resolved characterization combined with template infiltration experiments reveals that the exceptional penetrability of sc-CO_(2) enables framework formation even within confined micropores and allows for precise morphological tuning of COFs.Furthermore,we demonstrate that weak intermolecular forces such as interlayer electrostatic repulsions and hydrogen bonding can be amplified under supercritical fluid conditions to modulate crystal morphology,leading to the formation of rare helical COF crystals and enabling structure manipulation via rational side-group engineering.Single-crystalline COFs exhibit specific properties and potential applications,particularly in nonlinear optics,optoelectronics,and chemical sensing.These crystals display high second harmonic generation efficiencies due to their noncentrosymmetric packing,as well as robust third-order nonlinear responses enabled by chromophore alignment andπ-electron delocalization.In optoelectronic applications,dual-state COF phototransistors demonstrate room-temperature responsivity of∼4.6×1010 A·W−1 and detectivity of 1.62×1016 Jones,enabling high-contrast neuromorphic imaging under low-light and aqueous conditions.In chemical sensing applications,COF/graphene heterostructures synthesized via this method deliver unprecedented detection limits,down to 10−19 M for methylglyoxal and 10−10 M for mercury ions in biofluids,by integrating photochemical gating effects and exploiting ordered charge-transfer interfaces.Overall,this Account establishes the supercritical solvothermal method as a general and scalable platform for single-crystal COF synthesis.It not only broadens the synthetic scope to previously inaccessible topologies and linkage chemistries but also paves the way for the integration of COFs into high-performance photonic,electronic,and biomedical devices.Future opportunities lie in tuning fluid dynamics for dimensionality control,coupling with nucleation or competitive reaction strategies to access new architectures,and extending the kinetic framework to guide crystallization in other polymeric and supramolecular materials.
基金supported by the National Key Laboratory of Agricultural Equipment Technologysupported by the National Natural Science Foundation of China(32271979)。
文摘Detecting trace pesticide residues in food products is crucial for ensuring food safety.Terahertz technology has demonstrated significant advantages in chemical and biological sensing by utilizing the vibrational signatures inherent to molecules in the terahertz spectrum and leveraging the amplified electric fields facilitated by metamaterials.In this work,we introduce a novel method for imidacloprid(IMI)pesticide residue detection using the rod-shaped terahertz metamaterial(RSTM)with a composite interface of gold and conductive polymer polyaniline(PANI).The core mechanism of this method relies on the binding of IMI to PANI,which alters the resonance intensity and frequency of the Au-PANI-RSTM.Specifically,the RSTM parameters are determined using computer simulation technology(CST),and the RSTM structure is engraved on the Au-PANI surface using laser direct writing technology.Further characterization using mid-infrared spectroscopy(MIR)and X-ray photoelectron spectroscopy(XPS)techniques reveals that the stable bonding between PANI and IMI is facilitated by hydrogen bonding and covalent bonding.The detection limit of Au-PANI-RSTM deposited with 20 segments for IMI is 0.46 ppm,which complies with the maximum residue limit for IMI stipulated in the Chinese National Standard.
基金The study was supported in part by the Global Challenges for a Third Century(GCTC)project at University of Michigan.
文摘This paper reports a complete micro gas chromatography(μGC)system in which all the components are lithographically microfabricated and electronically interfaced.The components include a bi-directional Knudsen pump,a preconcentrator,separation columns and a pair of capacitive gas detectors;together,these form the iGC3.c2 system.All the fluidic components of the system are fabricated by a common three-mask lithographic process.The Knudsen pump is a thermomolecular pump that provides air flow to theμGC without any moving parts.The film heaters embedded in the separation columns permit temperature programming.The capacitive detectors provide complementary response patterns,enhancing vapor recognition and resolving coeluting peaks.With the components assembled on printed circuit boards,the system has a footprint of 8×10 cm^(2).Using room air as the carrier gas,the system is used to experimentally demonstrate the analysis of 19 chemicals with concentration levels on the order of parts per million(p.p.m.)and parts per billion(p.p.b.).The tested chemicals include alkanes,aromatic hydrocarbons,aldehydes,halogenated hydrocarbons and terpenes.This set of chemicals represents a variety of common indoor air pollutants,among which benzene,toluene and xylenes(BTX)are of particular interest.
基金supported by Natural Science Foundation of Xin-jiang(2022D01E03)National Natural Science Foundation of China(21974150,U1903306)+1 种基金the Youth Innovation Promotion Association,CAS(NO.2018474)Key Research Program of Frontier Sciences(CAS Grant No.ZDBS-LY-JSC029).
文摘The engineered biomimetic sensors can not only realize the action of organs,but also combine functional materials as in vitro organs by simulating the response of biological organs to different environmental signals.Artificial nose is a concept proposed by imitating biological olfactory system,simulating olfactory nerve cells,olfactory bulb and olfactory cortex through different materials to realize olfactory function.The sensor array used to sense external gas stimulation can be analyzed based on different recognition principles through different original signals such as optics,electricity,electrochemistry and bioelectricity.Furthermore,combined with pattern recognition and microarray technology,artificial nose can be highly integrated with biocompatible and other important properties to achieve in vitro application.The design principle and necessary components of artificial nose are introduced in this paper including sensing structure,recognition system and functional module.At the same time,the potential development prospects of molecular recognition technology,polymer-based materials and microarray integration in artificial nose are prospected.
