Shape dependent stripping behavior of Au nanoparticles toward arsenic detection: evidence of enhanced sensitivity on the Au (111) facet

Abstract

The Au (111) face has an advantage in As(III) detection, reported in earlier studies through the methods of simulation and computation, but unfortunately there is no experimental evidence. Here, a comparative study of gold cubes (110), octahedra (111), and rhombic dodecahedra (110) toward the detection of arsenic has been reported for the first time. The Au (111) face was found to exhibit the highest sensitivity compared with Au (100) and (110) surfaces in our experimental research. A reasonable mechanism based on the deposition process and binding energies was provided. The deposition process is a multiple-step, multiple-electron electrochemical reaction and the transfer step of the first accepted electron is the rate-determining step. This work presents an important insight into a new route to realize the improvement of sensitivity in the electrochemical sensing of As(III).