Colorimetric nanoprobes are frequently employed to construct sensitive sensors via various strategies.In this work,a novel strategy for simple and ultrasensitive sensing of iodide(I_(−))was constructed based on Cu^(2+...Colorimetric nanoprobes are frequently employed to construct sensitive sensors via various strategies.In this work,a novel strategy for simple and ultrasensitive sensing of iodide(I_(−))was constructed based on Cu^(2+)-assisted generation of Au@AgI core/shell nanorods(NRs),by etching silver-coated gold nanorods(Ag@Au NRs).Ag@Au NRs were first prepared and characterized with UV-visible spectroscopy,transmission electron microscopy,high-angle annular dark-field scanning transmission electron microscopy,and energy-dispersive X-ray spectroscopy before and after iodide treatment.The mechanism of detection was based on the generation of AgI shells via etching Ag shells by I_(2),which was produced from the oxidation of I_(−)with Cu^(2+),resulting in the peak shift of localized surface plasmon resonance(LSPR)while the color changed from green,blue to light-violet.The red-shift of the longitudinal LSPR peak had a linear relationship with I_(−)concentration in the range of 0-50μmol/L with a correlation coefficient of 0.982.Furthermore,the proposed method was used for the quantitative detection of I_(−)in real samples and outstanding recoveries in the range of 91-106%with relative standard deviations lower than 2.5%were observed.展开更多
基金This study was supported by the National Natural Science Foundation of China(21876206 and 21904055)the Nature Science Foundation of Fujian Province(2021H6033,2020J05164).
文摘Colorimetric nanoprobes are frequently employed to construct sensitive sensors via various strategies.In this work,a novel strategy for simple and ultrasensitive sensing of iodide(I_(−))was constructed based on Cu^(2+)-assisted generation of Au@AgI core/shell nanorods(NRs),by etching silver-coated gold nanorods(Ag@Au NRs).Ag@Au NRs were first prepared and characterized with UV-visible spectroscopy,transmission electron microscopy,high-angle annular dark-field scanning transmission electron microscopy,and energy-dispersive X-ray spectroscopy before and after iodide treatment.The mechanism of detection was based on the generation of AgI shells via etching Ag shells by I_(2),which was produced from the oxidation of I_(−)with Cu^(2+),resulting in the peak shift of localized surface plasmon resonance(LSPR)while the color changed from green,blue to light-violet.The red-shift of the longitudinal LSPR peak had a linear relationship with I_(−)concentration in the range of 0-50μmol/L with a correlation coefficient of 0.982.Furthermore,the proposed method was used for the quantitative detection of I_(−)in real samples and outstanding recoveries in the range of 91-106%with relative standard deviations lower than 2.5%were observed.
