title: How many molecules are required to obtain a steady faradaic current from mediated electron transfer at a single nanoparticle on a supporting surface?
abstract: We investigate the chronoamperometric noise characteristics of electron-transfer reactions occurring on single nanoparticles (NPs) and assemblies of well-separated NPs on a supporting surface. To this end, we combine a formerly described expression for the steady-state current of a single particle with the shot-noise model and derive an expression for the signal-to-noise ratio as a function of bulk concentration and particle radius. Our findings are supported by random-walk simulations, which closely match the analytical results.
authors.affiliation: Physical and Theoretical Chemistry Laboratory, Department of Chemistry, Oxford University, South Parks Road, Oxford OX1 3QZ (UK).
authors.forename: Enno
authors.initials: E
authors.lastname: Kätelhön
authors.forename: Kay J
authors.initials: KJ
authors.lastname: Krause
authors.forename: Bernhard
authors.initials: B
authors.lastname: Wolfrum
authors.forename: Richard G
authors.initials: RG
authors.lastname: Compton
keywords: analytical methods; electrochemistry; nanoparticles; noise spectroscopy; random walks