There is a rich of electric phenomena ubiquitously existing in novel quantum materials and advanced electronic devices.Microscopic understanding of the underlying physics relies on the sensitive and quantitative measu...There is a rich of electric phenomena ubiquitously existing in novel quantum materials and advanced electronic devices.Microscopic understanding of the underlying physics relies on the sensitive and quantitative measurements of the electric field,electric current,electric potential,and other related physical quantities with a spatial resolution down to nanometers.Combined with a scanning probe microscope(SPM),the emergent quantum sensors of atomic/nanometer size provide promising platforms for imaging various electric parameters with a sensitivity beyond a single electron/charge.In this perspective,we introduce the working principle of such newly developed technologies,which are based on the strong sensitivity of quantum systems to external disturbances.Then we review the recent applications of those quantum sensors in nanoscale electric sensing and imaging,including a discussion of their privileges over conventional SPM techniques.Finally,we propose some promising directions for the future developments and optimizations of quantum sensors in nanoscale electric sensing and imaging.展开更多
CdSe/CdS quantum dots （QDs） functionalized by thiourea （TU） were synthesized and used as a fluorescent sensor for mercury ion detection. The TU-functionalized QDs were prepared by bonding TU via electrostatic inte...CdSe/CdS quantum dots （QDs） functionalized by thiourea （TU） were synthesized and used as a fluorescent sensor for mercury ion detection. The TU-functionalized QDs were prepared by bonding TU via electrostatic interaction to the core/shell CdSe/CdS QDs after capping with thioglycolic acid （TGA）. It was observed that the fluorescence of the functionalized QDs was quenched upon the addition of Hg^2＋. The quantitative detection of Hg^2＋ with this fluorescent sensor could be conducted based on the linear relationship between the extent of quenching and the concentration of Hg^2＋ added in the range of 1-300 μg.L^-1, A detection limit of 0.56 μg.L^-1 was achieved. The sensor showed superior selectivity for Hg^2＋ and was successfully applied to the determination of mercury in environmental samples with satisfactory results展开更多
We prepare of ZnO quantum dots embedded in polyvinylpyrrolidone (PVP) matrix and report it’s working as ethanol sensor. The samples have been prepared via quenching technique where bulk ZnO powder is calcined at very...We prepare of ZnO quantum dots embedded in polyvinylpyrrolidone (PVP) matrix and report it’s working as ethanol sensor. The samples have been prepared via quenching technique where bulk ZnO powder is calcined at very high temperature of 1200°C and then quenched into ice cold polyvinylpyrrolidone solution. Thee acteiut the samples specimen have been characterized by using UV/VIS spectroscopy, X-ray diffracttion study and high resolution transmission electron microscopy (HRTEM). These studies indicate the sizes of quantum dots to be within 10 nm. The prepared quantum dot samples have been examined for ethanol vapour sensing by exploring the variation of their resistance with time at different operating temperatures. It has been revealed that ZnO quantum dots can sense ethanol at low operating (230°C) temperature with less response time.展开更多
基金funding provided by Shanghai Jiao Tong Universitysupported by the National Key R&D Program under Grant Nos 2021YFA1400500+2 种基金the National Natural Science Foundation of China under Grant Nos 11888101,21725302,and U22A20260the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant Nos XDB28000000support from the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘There is a rich of electric phenomena ubiquitously existing in novel quantum materials and advanced electronic devices.Microscopic understanding of the underlying physics relies on the sensitive and quantitative measurements of the electric field,electric current,electric potential,and other related physical quantities with a spatial resolution down to nanometers.Combined with a scanning probe microscope(SPM),the emergent quantum sensors of atomic/nanometer size provide promising platforms for imaging various electric parameters with a sensitivity beyond a single electron/charge.In this perspective,we introduce the working principle of such newly developed technologies,which are based on the strong sensitivity of quantum systems to external disturbances.Then we review the recent applications of those quantum sensors in nanoscale electric sensing and imaging,including a discussion of their privileges over conventional SPM techniques.Finally,we propose some promising directions for the future developments and optimizations of quantum sensors in nanoscale electric sensing and imaging.
基金the financial support from the National Natural Science Foundation of China (Nos. 20345006 and 20575043)
文摘CdSe/CdS quantum dots （QDs） functionalized by thiourea （TU） were synthesized and used as a fluorescent sensor for mercury ion detection. The TU-functionalized QDs were prepared by bonding TU via electrostatic interaction to the core/shell CdSe/CdS QDs after capping with thioglycolic acid （TGA）. It was observed that the fluorescence of the functionalized QDs was quenched upon the addition of Hg^2＋. The quantitative detection of Hg^2＋ with this fluorescent sensor could be conducted based on the linear relationship between the extent of quenching and the concentration of Hg^2＋ added in the range of 1-300 μg.L^-1, A detection limit of 0.56 μg.L^-1 was achieved. The sensor showed superior selectivity for Hg^2＋ and was successfully applied to the determination of mercury in environmental samples with satisfactory results
文摘We prepare of ZnO quantum dots embedded in polyvinylpyrrolidone (PVP) matrix and report it’s working as ethanol sensor. The samples have been prepared via quenching technique where bulk ZnO powder is calcined at very high temperature of 1200°C and then quenched into ice cold polyvinylpyrrolidone solution. Thee acteiut the samples specimen have been characterized by using UV/VIS spectroscopy, X-ray diffracttion study and high resolution transmission electron microscopy (HRTEM). These studies indicate the sizes of quantum dots to be within 10 nm. The prepared quantum dot samples have been examined for ethanol vapour sensing by exploring the variation of their resistance with time at different operating temperatures. It has been revealed that ZnO quantum dots can sense ethanol at low operating (230°C) temperature with less response time.
