Gold nanoparticle ensembles allow mechanistic insights into electrochemical processes.

Gold-nanoparticle-modified electrodes find wide and diverse applications in the area of electrochemistry. We demonstrate for the first time that gold-nanoparticle-modified electrodes can provide mechanistic information and we exemplify this with the electrochemical deposition of arsenic(III). Our approach of using nanoparticle ensembles is a facile and economical methodology that provides an alternative to using expensive gold single-crystal electrodes that require careful surface preparation before each measurement.