Adsorption-Mediated Electrochemical Sensing of Halides.

A new strategy for detecting halides is presented that employs gold electrodes plated to expose a monolayer of silver atoms. Cl , Br , and I ions each adsorb onto this surface and stochastically produce electrochemical changes (see picture; upd=underpotentially deposited) in the stripping characteristic of the silver layer that reflect the identity and surface coverage of these halides. The latter provides measurements that relate to the solution concentrations of the halides.