An Investigation of Adsorption Enantioselectivity of Faceted Polycrystalline Platinum and Gold Electrodes

Abstract

The present work presents an investigation of the enantioselectivity of (111) and (100) faceted polycrystalline platinum and gold electrodes. Electrochemical faceting of these polycrystalline electrodes was carried out by application of a suitable square wave that induces preferential dissolution of some crystallographic planes. The chirality of the produced surfaces was investigated by testing the ability of the prepared surfaces to discriminate voltammetrically between some amino acids and sugar enantiomers upon adsorption at the above-mentioned surfaces. The results indicate that all the polycrystalline electrodes were achiral. Faceted platinum and gold electrodes, however, possess some chirality depending on the surface orientation. Pt(111) faceted electrodes were able to discriminate between enantiomers of the investigated phenylalanine and serine. Pt(100) faceted electrodes also were able to discriminate between the investigated enantiomers, but to a lower extent. Faceted gold electrodes showed a similar ability of discrimination between the investigated phenylalanine and serine enantiomers.