摘要
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.
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).
