Surface interrogation mode of scanning electrochemical microscopy for oxidation study of adsorbed CO generated from serine on platinum

We report a new method for detection and oxidation of adsorbed carbon monoxide (CO(ads)) generated from serine on a polycrystalline platinum ultramicroelectrode (UME) by bromine (Br2) using in situ surface interrogation (SI) mode of scanning electrochemical microscopy (SECM). In the SI mode, tip and substrate are both Pt UMEs, and CO(ads) on Pt substrate, generated from serine, can be oxidized by the tip-generated Br2 giving a positive response. Dosing CO(ads) from serine instead of purging CO gas expands the newly introduced reaction of Br2 with CO(ads) and further enhances the hope to get rid of CO(ads) on Pt for fuel cells.