Organic semiconductor materials have demonstrated extensive potential in the field of gas sensors due to the advantages including designable chemical structure,tunable physical and chemical properties.Through density ...Organic semiconductor materials have demonstrated extensive potential in the field of gas sensors due to the advantages including designable chemical structure,tunable physical and chemical properties.Through density functional theory(DFT)calculations,researchers can investigate gas sensing mechanisms,optimize,and predict the electronic structures and response characteristics of these materials,and thereby identify candidate materials with promising gas sensing applications for targeted design.This review concentrates on three primary applications of DFT technology in the realm of organic semiconductor-based gas sensors:(1)Investigating the sensing mechanisms by analyzing the interactions between gas molecules and sensing materials through DFT,(2)simulating the dynamic responses of gas molecules,which involves the behavior on the sensing interface using DFT combined with other computational methods to explore adsorption and diffusion processes,and(3)exploring and designing sensitive materials by employing DFT for screening and predicting chemical structures,thereby developing new sensing materials with exceptional performance.Furthermore,this review examines current research outcomes and anticipates the extensive application prospects of DFT technology in the domain of organic semiconductor-based gas sensors.These efforts are expected to provide valuable insights for further indepth exploration of DFT applications in sensor technology,thereby fostering significant advancements and innovations in the field.展开更多
A new kind of fiber optic oxygen sensing material based on the fluorescence quenching of Ru（bpy）3Cl2 was prepared by the themo-polymerization method. The ruthenium dye was immobilized in N, N-methylene bisacrylamide...A new kind of fiber optic oxygen sensing material based on the fluorescence quenching of Ru（bpy）3Cl2 was prepared by the themo-polymerization method. The ruthenium dye was immobilized in N, N-methylene bisacrylamide（MBBA） polymer by physically trapping while MBBA was covalently crosslinked on the glass micro-beads by NaHSO3-O2-MnSO4 initiator system. The lock-in amplifyication technology was used for the detection of their sensing properties. The influences of indicator concentration, glass micro-beads diameter, post polymerization time, concentration and reaction time of glutaraldehyde on the properties of sensing materials were studied. To optimize the influencing factors to the sensing materials, the indicator concentration of 0.7 g/L, glass micro-beads diameter of 0.3 mm, post polymerization time of 5 h were achieved. The immobilization stability of ruthenium dye and the performance of the sensing materials were improved by the new polymerization system. An absolute detection limit of 3×10-6 （V/V） and the response time of 10 s were obtained. This kind of sensing materials has good stability and their life time is 2 years.展开更多
Nd-doped(2%,5%,10% in mass ratio) SnO2 powders were prepared via a facile hydrothermal procedure.The as-prepared samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),and Brunauer-Emme...Nd-doped(2%,5%,10% in mass ratio) SnO2 powders were prepared via a facile hydrothermal procedure.The as-prepared samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),and Brunauer-Emmett-Teller(BET) specific surface area analyzers.Results showed that the Nd-doped SnO2 samples had more uniform and smaller primary particles compared with the pure sample,the particle size of the doped SnO2 decreased gradually with the increase of Nd,and the specific surface area also increased with the increase of the doped Nd.When used as gas sensing materials,the 5% and 10% Nd-doped sample showed high sensitivity and selectivity to ethanol.Furthermore,the Nd-doped sample showed fast response and recovery time to ethanol gas.This could be attributed to their small diameter,large surface area and Nd element doping.展开更多
Among various gas sensing materials, metal oxide semiconductors have shown great potential as resistive type sensors. The ordered porous structural metal oxide semiconductors with well-defined meso- or macro-pores che...Among various gas sensing materials, metal oxide semiconductors have shown great potential as resistive type sensors. The ordered porous structural metal oxide semiconductors with well-defined meso- or macro-pores chemically synthesized via soft-templating method and nanocasting strategy have high porosity, highly interconnected pore channels and high surface area with enormous active sites for interacting with gaseous molecules. These features enable them good performance in gas sensing, including high sensitivity, fast response and recovery, good selectivity. This review gives a comprehensive summary about the porous metal oxides with focus on the synthesis methods, structure related properties, as well as the modification strategies for gas sensing improved performances.展开更多
Chemical sensor arrays can obtain more comprehensive analyte information through high-dimensional data.It is of great significance in the analysis of multi-component complex samples.This review summarizes the developm...Chemical sensor arrays can obtain more comprehensive analyte information through high-dimensional data.It is of great significance in the analysis of multi-component complex samples.This review summarizes the development and status of chemical sensor arrays.We focused on the design of chemical sensor arrays based on various sensing materials.In addition,several pattern recognition methods in chemometrics are introduced.And applications of chemical sensor arrays in food monitoring,medical diagnosis,and environmental monitoring are illustrated.Based on the analysis of the limitations of current sensor array technology,the direction of the array is also predicted.This review aims to help the broad readership understand the research state of chemical sensor arrays and their development prospects.展开更多
A new method to reduce the reflection-induced phase between the two orthogonal components of the linearly polarized light after the reflections is presented. This kind of sensor head is easier to fabricate and adjust ...A new method to reduce the reflection-induced phase between the two orthogonal components of the linearly polarized light after the reflections is presented. This kind of sensor head is easier to fabricate and adjust than that whose internal reflection is at critical angle.展开更多
Real-time thermal sensing through flexible temperature sensors in extreme environments is critically essential for precisely monitoring chemical reactions,propellant combustions,and metallurgy processes.However,despit...Real-time thermal sensing through flexible temperature sensors in extreme environments is critically essential for precisely monitoring chemical reactions,propellant combustions,and metallurgy processes.However,despite their low response speed,most existing thermal sensors and related sensing materials will degrade or even lose their sensing performances at either high or low temperatures.Achieving a microsecond response time over an ultrawide temperature range remains challenging.Here,we design a flexible temperature sensor that employs ultrathin and consecutive Mo_(1−x)W_(x)S_(2) alloy films constructed via inkjet printing and a thermal annealing strategy.The sensing elements exhibit a broad work range(20 to 823 K on polyimide and 1,073 K on flexible mica)and a record-low response time(about 30μs).These properties enable the sensors to detect instantaneous temperature variations induced by contact with liquid nitrogen,water droplets,and flames.Furthermore,a thermal sensing array offers the spatial mapping of arbitrary shapes,heat conduction,and cold traces even under bending deformation.This approach paves the way for designing unique sensitive materials and flexible sensors for transient sensing under harsh conditions.展开更多
Highly sensitive and selective detection against specific target gases, especially at low-ppb （part per bil- lion） level, remain a great number of challenges in gas sensor applications. In this paper, we first prese...Highly sensitive and selective detection against specific target gases, especially at low-ppb （part per bil- lion） level, remain a great number of challenges in gas sensor applications. In this paper, we first present an ordered mesoporous NiFe204 for highly sensitive and selective detection against low-ppb toluene. A series of mesoporous NiFe204 materials were synthesized by templating from mesoporous silica KIT-6 and its framework thickness was reduced from 8.5 to 5 nm by varying the pore size of KIT-6 from 9.4 to 5.6 nm, accompanied with the increase of the specific surface area from 134 to 216 m^2 g^-1. The ordered mesoporous NiFe2O4 with both ultrathin framework of 5 nm and large specific surface area of up to 216 m^2 g^-1 exhibits a highest response （Rgas/Ralr-1 = 77.3） toward 1,000 ppb toluene at 230℃ and is nearly 7.3 and 76.7 times higher than those for the NiFe204 replica with thick framework and its bulk counter- part respectively, which also possesses a quite low limit of detection （〈2 ppb）, and good selectivity.展开更多
Drug abuse directly endangers human health and social security,hence its sensitive and rapid detection is vitally important.In recent years,organic film-based fluorescent sensing technology has attracted more and more...Drug abuse directly endangers human health and social security,hence its sensitive and rapid detection is vitally important.In recent years,organic film-based fluorescent sensing technology has attracted more and more attention in the detection of drugs and explosives due to its advantages of simple operation and rapid detection.For film-based fluorescent sensors,in addition to sensitive materials,the surface morphology of the film is also an important factor affecting the performance.In previous studies,the regulation of surface morphology mainly depends on concentration changes or complex templates.Here,a novel fluorescent polymer probe was designed and synthesized,and a simple and efficient ultraviolet(UV)-ozone substrate treatment method is used to adjust their surface morphology.The results show that film has an excellent fluorescence enhancement effect upon exposure to methylphenethylamine(MPEA,a simulant of methamphetamine)vapor.The sensing effect of the film is significantly improved after UV-ozone substrate treatment,and the limit of detection was decreased by 10.4 times from 2.59 to 0.25 ppm.Further experiments show that the sensing performance of other fluorescent probe can also be improved by the UV-ozone substrate treatment.This convenient and general method may become a very effective approach to improve the performance of film-based fluorescent sensors.展开更多
Electrical resistance strain gauges(SGs) are useful tools for experimental stress analysis and the strain sensing elements in many electromechanical transducers including load cells,pressure transducers,torque meters,...Electrical resistance strain gauges(SGs) are useful tools for experimental stress analysis and the strain sensing elements in many electromechanical transducers including load cells,pressure transducers,torque meters,accelerometers,force cells,displacement transducers and so forth.The commonly used commercial crystalline strain sensing materials of SGs are in the form of wire or foil of which performance and reliability is not good enough due to their low electrical resistivity and incapacity to get thin thickness.Smaller SGs with single straight strand strain sensing materials,which are called ideal SG,are highly desirable for more than seven decades since the first SG was invented.Here,we show the development of a type of minuscule length scale strain gauge by using a bare and single straight strand metallic glassy fiber(MGF) with high resistivity,much smaller lengthscale,high elastic limits(2.16%) and especially the super piezoresistance effect.We anticipate that our metallic glassy fiber strain gauge(MGFSG),which moves toward the ideal SGs,would have wide applications for electromechanical transducers and stress analysis and catalyze development of more micro-and nanoscale metallic glass applications.展开更多
基金supported by National Natural Science Foundation of China(Nos.92263109 and 61904188)the Shanghai Rising-Star Program(No.22QA1410400)。
文摘Organic semiconductor materials have demonstrated extensive potential in the field of gas sensors due to the advantages including designable chemical structure,tunable physical and chemical properties.Through density functional theory(DFT)calculations,researchers can investigate gas sensing mechanisms,optimize,and predict the electronic structures and response characteristics of these materials,and thereby identify candidate materials with promising gas sensing applications for targeted design.This review concentrates on three primary applications of DFT technology in the realm of organic semiconductor-based gas sensors:(1)Investigating the sensing mechanisms by analyzing the interactions between gas molecules and sensing materials through DFT,(2)simulating the dynamic responses of gas molecules,which involves the behavior on the sensing interface using DFT combined with other computational methods to explore adsorption and diffusion processes,and(3)exploring and designing sensitive materials by employing DFT for screening and predicting chemical structures,thereby developing new sensing materials with exceptional performance.Furthermore,this review examines current research outcomes and anticipates the extensive application prospects of DFT technology in the domain of organic semiconductor-based gas sensors.These efforts are expected to provide valuable insights for further indepth exploration of DFT applications in sensor technology,thereby fostering significant advancements and innovations in the field.
基金the Project of National Nature Science Foundation of China(No.60377032)Key Project of National Nature Science Foundation of China(No.60537050)
文摘A new kind of fiber optic oxygen sensing material based on the fluorescence quenching of Ru（bpy）3Cl2 was prepared by the themo-polymerization method. The ruthenium dye was immobilized in N, N-methylene bisacrylamide（MBBA） polymer by physically trapping while MBBA was covalently crosslinked on the glass micro-beads by NaHSO3-O2-MnSO4 initiator system. The lock-in amplifyication technology was used for the detection of their sensing properties. The influences of indicator concentration, glass micro-beads diameter, post polymerization time, concentration and reaction time of glutaraldehyde on the properties of sensing materials were studied. To optimize the influencing factors to the sensing materials, the indicator concentration of 0.7 g/L, glass micro-beads diameter of 0.3 mm, post polymerization time of 5 h were achieved. The immobilization stability of ruthenium dye and the performance of the sensing materials were improved by the new polymerization system. An absolute detection limit of 3×10-6 （V/V） and the response time of 10 s were obtained. This kind of sensing materials has good stability and their life time is 2 years.
基金Project supported by the National Natural Science Foundation of China (20871107)He'nan Outstanding Youth Science Fund (0612002700)the Natural Science Foundation of the Education Department of Henan Province (2009A150031)
文摘Nd-doped(2%,5%,10% in mass ratio) SnO2 powders were prepared via a facile hydrothermal procedure.The as-prepared samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),and Brunauer-Emmett-Teller(BET) specific surface area analyzers.Results showed that the Nd-doped SnO2 samples had more uniform and smaller primary particles compared with the pure sample,the particle size of the doped SnO2 decreased gradually with the increase of Nd,and the specific surface area also increased with the increase of the doped Nd.When used as gas sensing materials,the 5% and 10% Nd-doped sample showed high sensitivity and selectivity to ethanol.Furthermore,the Nd-doped sample showed fast response and recovery time to ethanol gas.This could be attributed to their small diameter,large surface area and Nd element doping.
基金supported by the National Natural Science Foundation of China(Nos.51372041,51422202, and 21673048)the "Shu Guang" Project(No. 13SG02)supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation+3 种基金the National Youth Top-notch Talent Support Program in China, China Postdoctoral Science Foundation(No. KLH1615138)Shanghai Nature Science Foundation of China(Nos. 14ZR1416600 and 15ZR1402000)Shanghai Pujiang Program, China(No.16PJ1401100)the International Scientific Partnership Program ISPP at King Saud University for funding this research work through ISPP# 0094
文摘Among various gas sensing materials, metal oxide semiconductors have shown great potential as resistive type sensors. The ordered porous structural metal oxide semiconductors with well-defined meso- or macro-pores chemically synthesized via soft-templating method and nanocasting strategy have high porosity, highly interconnected pore channels and high surface area with enormous active sites for interacting with gaseous molecules. These features enable them good performance in gas sensing, including high sensitivity, fast response and recovery, good selectivity. This review gives a comprehensive summary about the porous metal oxides with focus on the synthesis methods, structure related properties, as well as the modification strategies for gas sensing improved performances.
基金funded by Natural Science Foundation of Heilongjiang Province(No.LH2022B004)Fundamental Research Funds for the Central Universities(No.2572022DJ01)+1 种基金111 Project(No.B20088)Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team)。
文摘Chemical sensor arrays can obtain more comprehensive analyte information through high-dimensional data.It is of great significance in the analysis of multi-component complex samples.This review summarizes the development and status of chemical sensor arrays.We focused on the design of chemical sensor arrays based on various sensing materials.In addition,several pattern recognition methods in chemometrics are introduced.And applications of chemical sensor arrays in food monitoring,medical diagnosis,and environmental monitoring are illustrated.Based on the analysis of the limitations of current sensor array technology,the direction of the array is also predicted.This review aims to help the broad readership understand the research state of chemical sensor arrays and their development prospects.
文摘A new method to reduce the reflection-induced phase between the two orthogonal components of the linearly polarized light after the reflections is presented. This kind of sensor head is easier to fabricate and adjust than that whose internal reflection is at critical angle.
基金supported by the National Natural Science Foundation of China(62304182,62371397,and 62288102)the Natural Science Foundation of Shaanxi Province(2023-JC-YB-495)+1 种基金the Fundamental Research Funds for the Central Universitiesthe start-up funds from Northwestern Polytechnical University(G2022WD01001 and 23GH02021).
文摘Real-time thermal sensing through flexible temperature sensors in extreme environments is critically essential for precisely monitoring chemical reactions,propellant combustions,and metallurgy processes.However,despite their low response speed,most existing thermal sensors and related sensing materials will degrade or even lose their sensing performances at either high or low temperatures.Achieving a microsecond response time over an ultrawide temperature range remains challenging.Here,we design a flexible temperature sensor that employs ultrathin and consecutive Mo_(1−x)W_(x)S_(2) alloy films constructed via inkjet printing and a thermal annealing strategy.The sensing elements exhibit a broad work range(20 to 823 K on polyimide and 1,073 K on flexible mica)and a record-low response time(about 30μs).These properties enable the sensors to detect instantaneous temperature variations induced by contact with liquid nitrogen,water droplets,and flames.Furthermore,a thermal sensing array offers the spatial mapping of arbitrary shapes,heat conduction,and cold traces even under bending deformation.This approach paves the way for designing unique sensitive materials and flexible sensors for transient sensing under harsh conditions.
基金supported by the National First-Rate Discipline Construction Project of Ningxia(NXYLXK2017A04,2017CET02KY03,and 2017CET04KY05)the National Natural Science Foundation of China(51362024,21006116,and 51672138)+2 种基金the Foundation of State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering(2016–19)National Science Fund for Distinguished Young Scholars(21325105)the West Light Foundation of the Chinese Academy of Science
文摘Highly sensitive and selective detection against specific target gases, especially at low-ppb （part per bil- lion） level, remain a great number of challenges in gas sensor applications. In this paper, we first present an ordered mesoporous NiFe204 for highly sensitive and selective detection against low-ppb toluene. A series of mesoporous NiFe204 materials were synthesized by templating from mesoporous silica KIT-6 and its framework thickness was reduced from 8.5 to 5 nm by varying the pore size of KIT-6 from 9.4 to 5.6 nm, accompanied with the increase of the specific surface area from 134 to 216 m^2 g^-1. The ordered mesoporous NiFe2O4 with both ultrathin framework of 5 nm and large specific surface area of up to 216 m^2 g^-1 exhibits a highest response （Rgas/Ralr-1 = 77.3） toward 1,000 ppb toluene at 230℃ and is nearly 7.3 and 76.7 times higher than those for the NiFe204 replica with thick framework and its bulk counter- part respectively, which also possesses a quite low limit of detection （〈2 ppb）, and good selectivity.
基金supported by the National Natural Science Foundation of China(Nos.62022085,61901456,61831021,61731016,and 61771460)the National Key R&D Program of China(No.2018AAA0103100)the Science and Technology Commission of Shanghai Municipality(Nos.19YF1455700 and 19142203500).
文摘Drug abuse directly endangers human health and social security,hence its sensitive and rapid detection is vitally important.In recent years,organic film-based fluorescent sensing technology has attracted more and more attention in the detection of drugs and explosives due to its advantages of simple operation and rapid detection.For film-based fluorescent sensors,in addition to sensitive materials,the surface morphology of the film is also an important factor affecting the performance.In previous studies,the regulation of surface morphology mainly depends on concentration changes or complex templates.Here,a novel fluorescent polymer probe was designed and synthesized,and a simple and efficient ultraviolet(UV)-ozone substrate treatment method is used to adjust their surface morphology.The results show that film has an excellent fluorescence enhancement effect upon exposure to methylphenethylamine(MPEA,a simulant of methamphetamine)vapor.The sensing effect of the film is significantly improved after UV-ozone substrate treatment,and the limit of detection was decreased by 10.4 times from 2.59 to 0.25 ppm.Further experiments show that the sensing performance of other fluorescent probe can also be improved by the UV-ozone substrate treatment.This convenient and general method may become a very effective approach to improve the performance of film-based fluorescent sensors.
基金support from the National Natural Science Foundation of China (Grant Nos. 50921091 and 50731008)the National Basic Research Program of China (973) (Grant Nos. 2007CB613904 and2010CB731603)
文摘Electrical resistance strain gauges(SGs) are useful tools for experimental stress analysis and the strain sensing elements in many electromechanical transducers including load cells,pressure transducers,torque meters,accelerometers,force cells,displacement transducers and so forth.The commonly used commercial crystalline strain sensing materials of SGs are in the form of wire or foil of which performance and reliability is not good enough due to their low electrical resistivity and incapacity to get thin thickness.Smaller SGs with single straight strand strain sensing materials,which are called ideal SG,are highly desirable for more than seven decades since the first SG was invented.Here,we show the development of a type of minuscule length scale strain gauge by using a bare and single straight strand metallic glassy fiber(MGF) with high resistivity,much smaller lengthscale,high elastic limits(2.16%) and especially the super piezoresistance effect.We anticipate that our metallic glassy fiber strain gauge(MGFSG),which moves toward the ideal SGs,would have wide applications for electromechanical transducers and stress analysis and catalyze development of more micro-and nanoscale metallic glass applications.
