Trimetallic Ag@Pt-Rh core-shell nanocubes modified anode for voltammetric sensing of dopamine and sulfanilamide

Abstract Core-shell structured catalysts have attracted numerous attention due to their high utilization of metallic atoms, abundance of active sites, and high catalytic activity. Herein, Ag@Pt-Rh core-shell nanocubes were prepared by overgrowth of Pt-Rh on selective facets of Ag nanocubes via co-titration method for electrochemical detection of micropollutants such as dopamine (DA) and sulfanilamide (SA). The morphology and elemental distribution of Ag@Pt-Rh core-shell nanocubes were studied by TEM and high-resolution XPS. Results show that the Pt and Rh atoms were distributed uniformly on the surface of the Ag nanocubes. The electrochemical characterizations indicate that Ag@Pt-Rh NCs exhibited wide linear ranges of 0.2-512 µM with detection limits of 12 nM for determination of DA and a linear range of 2.6-320 μM with detection limits of 270 nM for monitoring SA. Thus, the Ag@Pt-Rh core-shell NCs may serve as a model for developing electrochemical sensors to monitor other biomolecules and pollutants.