Graphene-based gas/vapor sensors have attracted much attention in recent years due to their variety of structures, unique sensing performances, room-temperature working conditions, and tremendous application prospects...Graphene-based gas/vapor sensors have attracted much attention in recent years due to their variety of structures, unique sensing performances, room-temperature working conditions, and tremendous application prospects, etc.Herein, we summarize recent advantages in graphene preparation, sensor construction, and sensing properties of various graphene-based gas/vapor sensors, such as NH_3, NO_2, H_2, CO, SO_2, H_2S, as well as vapor of volatile organic compounds.The detection mechanisms pertaining to various gases are also discussed. In conclusion part, some existing problems which may hinder the sensor applications are presented. Several possible methods to solve these problems are proposed, for example, conceived solutions, hybrid nanostructures, multiple sensor arrays, and new recognition algorithm.展开更多
Electrospun nanofibers of a polyaniline(PANi)/(+)-camphor-10-sulfonic acid(HCSA)/poly(ethylene oxide)(PEO)composite doped with different variants of graphene oxide(GO)were fabricated and evaluated as chemiresistor gas...Electrospun nanofibers of a polyaniline(PANi)/(+)-camphor-10-sulfonic acid(HCSA)/poly(ethylene oxide)(PEO)composite doped with different variants of graphene oxide(GO)were fabricated and evaluated as chemiresistor gas sensors operating at room temperature.A new strategy for enhancing PANi/PEO gas sensor performance is demonstrated using GO dopants reduced via thermal(trGO)or chemical(crGO)routes.By varying the chemical reduction duration(6 h,crGO-6 or 24 h,crGO-24),tunable enhancement of sensor response was achieved.Upon exposure to short-chain aliphatic alcohol vapors,the partially reduced crGO-6 dopant exhibited higher response than GO and crGO-24,suggesting that the dopant enhances sensor performance via increased electrical conductivity over neat GO,and enhanced hydrogen bonding capability over the further-reduced crGO-24 variant.Sensor arrays consisting of PANi/PEO doped with trGO,crGO-6 or crGO-24 moieties successfully identified methanol,ethanol,and 1-propanol vapors using principal component analysis(PCA).展开更多
We demonstrate the selective detection of hydrogen sulfide at breath concentration levels under humid airflow,using a self-validating 64-channel sensor array based on semiconducting single-walled carbon nanotubes(sc-S...We demonstrate the selective detection of hydrogen sulfide at breath concentration levels under humid airflow,using a self-validating 64-channel sensor array based on semiconducting single-walled carbon nanotubes(sc-SWCNTs).The reproducible sensor fabrication process is based on a multiplexed and controlled dielectrophoretic deposition of sc-SWCNTs.The sensing area is functionalized with gold nanoparticles to address the detection at room temperature by exploiting the affinity between gold and sulfur atoms of the gas.Sensing devices functionalized with an optimized distribution of nanoparticles show a sensitivity of 0.122%/part per billion(ppb)and a calculated limit of detection(LOD)of 3 ppb.Beyond the self-validation,our sensors show increased stability and higher response levels compared to some commercially available electrochemical sensors.The cross-sensitivity to breath gases NH3 and NO is addressed demonstrating the high selectivity to H2S.Finally,mathematical models of sensors’electrical characteristics and sensing responses are developed to enhance the differentiation capabilities of the platform to be used in breath analysis applications.展开更多
基金financial supports provided by the National Basic Research Program of China(2013CB932500)the National Natural Science Foundation of China(21171117 and 61574091)+3 种基金the Program for New Century Excellent Talents in University(NCET-12-0356)the Program of Shanghai Academic/Technology Research Leader(15XD1525200)Shanghai Jiao Tong University Agri-X Funding(Agri-X2015007)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning
文摘Graphene-based gas/vapor sensors have attracted much attention in recent years due to their variety of structures, unique sensing performances, room-temperature working conditions, and tremendous application prospects, etc.Herein, we summarize recent advantages in graphene preparation, sensor construction, and sensing properties of various graphene-based gas/vapor sensors, such as NH_3, NO_2, H_2, CO, SO_2, H_2S, as well as vapor of volatile organic compounds.The detection mechanisms pertaining to various gases are also discussed. In conclusion part, some existing problems which may hinder the sensor applications are presented. Several possible methods to solve these problems are proposed, for example, conceived solutions, hybrid nanostructures, multiple sensor arrays, and new recognition algorithm.
基金The authors would like to acknowledge financial support from United States NSF(CHE-1413449).
文摘Electrospun nanofibers of a polyaniline(PANi)/(+)-camphor-10-sulfonic acid(HCSA)/poly(ethylene oxide)(PEO)composite doped with different variants of graphene oxide(GO)were fabricated and evaluated as chemiresistor gas sensors operating at room temperature.A new strategy for enhancing PANi/PEO gas sensor performance is demonstrated using GO dopants reduced via thermal(trGO)or chemical(crGO)routes.By varying the chemical reduction duration(6 h,crGO-6 or 24 h,crGO-24),tunable enhancement of sensor response was achieved.Upon exposure to short-chain aliphatic alcohol vapors,the partially reduced crGO-6 dopant exhibited higher response than GO and crGO-24,suggesting that the dopant enhances sensor performance via increased electrical conductivity over neat GO,and enhanced hydrogen bonding capability over the further-reduced crGO-24 variant.Sensor arrays consisting of PANi/PEO doped with trGO,crGO-6 or crGO-24 moieties successfully identified methanol,ethanol,and 1-propanol vapors using principal component analysis(PCA).
基金the German Federal State of Saxony as part of the“SNIFFBOT:Sniffing Dangerous Gases with Immersive Robots”project under grant agreement number 100369691the German Federal Ministry of Education and Research(No.031B0298)。
文摘We demonstrate the selective detection of hydrogen sulfide at breath concentration levels under humid airflow,using a self-validating 64-channel sensor array based on semiconducting single-walled carbon nanotubes(sc-SWCNTs).The reproducible sensor fabrication process is based on a multiplexed and controlled dielectrophoretic deposition of sc-SWCNTs.The sensing area is functionalized with gold nanoparticles to address the detection at room temperature by exploiting the affinity between gold and sulfur atoms of the gas.Sensing devices functionalized with an optimized distribution of nanoparticles show a sensitivity of 0.122%/part per billion(ppb)and a calculated limit of detection(LOD)of 3 ppb.Beyond the self-validation,our sensors show increased stability and higher response levels compared to some commercially available electrochemical sensors.The cross-sensitivity to breath gases NH3 and NO is addressed demonstrating the high selectivity to H2S.Finally,mathematical models of sensors’electrical characteristics and sensing responses are developed to enhance the differentiation capabilities of the platform to be used in breath analysis applications.
