Electroactive Au@Ag nanoparticles driven electrochemical sensor for endogenous H2S detection.

In this work, a novel and facile electrochemical sensor is reported for the highly selective and sensitive detection of dissolved hydrogen sulfide (H2S), attributing to the redox reaction between Au@Ag core-shell nanoparticles (Au@Ag NPs) and H2S. 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 H2S, the Ag shell of Au@Ag NPs can be oxidized to Ag2S, 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 H2S is as low as 0.04 nM. The developed sensor shows significant prospects in the study of pathological processes related to the mechanism of H2S production.