Electroactive Au@Ag nanoparticles driven electrochemical sensor for endogenous HS detection.

In this work, a novel and facile electrochemical sensor is reported for the highly selective and sensitive detection of dissolved hydrogen sulfide (HS), attributing to the redox reaction between Au@Ag core-shell nanoparticles (Au@Ag NPs) and HS. Electroactive Au@Ag NPs not only possess excellent conductivity, but exhibit great electrochemical reactivity at 0.26 V due to the electrochemical oxidation from Ag° to Ag. In the presence of HS, the Ag shell of Au@Ag NPs can be oxidized to AgS, resulting in the decrease of differential pulse voltammetry (DPV) peak at 0.26 V. The electrochemical sensor exhibits a wide linear response range from 0.1 nM to 500 nM. The limit of detection (LOD) for HS is as low as 0.04 nM. The developed sensor shows significant prospects in the study of pathological processes related to the mechanism of HS production.