silver nanotriangles optochronometric tongue for determination and discrimination of halide ions

Halide ions including cl-, br- and i- ions are known as critical species for human health, and their appropriate amount of them can be very useful for body. in contrast, the excess amount of halide ions may cause serious problems including neurological dysfunction and endemic goiter[1]. due to the important roles of the halide ions in human health, the development of rapid and simple yet reliable probes for the detection of these species have attracted significant interest in recent years. hence, in this study, ag triangle nanoparticles (ag tnps) were exploited as colorimetric sensing element for the detection of halide ions [2, 3]. the halide ions (i-, br- and cl-) at different concentrations can etch the sharp vertices of ag tnps and produce semi-spherical agnps. consequently, changing the structures of ag tnps to agnps leads to a dramatic blue shift in the plasmon resonance band of ag tnps and changes the color from blue to yellow. therefore, the spectra changes, as a result of etching the ag tnps produced a unique color and spectra variation for each halide ions. given these halide ions have differential effect on the kinetic of etching ag ntps, a colorimetric sensor array has been developed to successfully discriminate halide ions with the help of pattern recognition analysis. finally, the capability of the sensor in quantitative and qualitative analysis of the halide ions in tap water was investigated by which the practicality of the proposed strategy was successfully verified.