The Use of Plasmonic Spectroscopy for Detecting Ultra-Low Concentrations of Substances

Abstract

This paper presents the results of research into the excitation of a surface electromagnetic wave (SEW) in Au/AgI and Au/Ag films contacting aqueous solutions of hydrogen peroxide (H2O2) and sodium chloride (NaCl). The dependences of the SEW excitation angle in the Kretschmann configuration on the interaction time of the solution with the metal film have been obtained. The effect of an aqueous H2O2 solution on the AgI and Ag film under prolonged exposure has been demonstrated. It has been shown that the dynamics of the excitation angle can be used to estimate the concentration of solutions with low and ultra-low concentrations. As an example, the results of using the technique for the analysis of aqueous solutions of NaCl are presented.