An Aptamer-Modified Nanogold Method for the Determination of Trace Ag⁺ Using Resonance Rayleigh Scattering as Detection Technique

Abstract

Aptamer was modified the gold nanoparticle (AuNP) to form stable aptamer-AuNP probe that was not gathered in the pH 7.2 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES) buffer solution and in the presence of NaCl. The Ag+ react with the aptamer-AuNP probe to fold a hairpin structure complex of Ag+-aptamer and release AuNPs that were aggregated to large particles, which lead to resonance Rayleigh scattering (RRS) peak at 596 nm enhancement. The enhanced value ΔI596nm is linear to Ag + concentration in the range of 6.7×10-8-1.33×10-6 mol/L. Thus, a new RRS methods were proposed for detection of Ag+, with high sensitivity, good selectivity and simplicity.