A novel two-step method was developed to prep. gold nanoparticles on boron-doped diamond (BDD) electrode. It consisted of sputter deposition of max. 15 equiv monolayers of gold, followed by a heat treatment at 400-600 Deg in air. The as-sputtered gold deposits were highly dispersed (estd. particle size of 2-7 nm) but also unstable, a continuous potential cycling in the stability region of sulfuric acid leading to complete loss of the deposited gold. Subsequent heat treatment of as-sputtered deposits resulted in formation of a stable population of nanosized gold particles characterized by SEM and cyclic voltammetry. Gold nanoparticles with an av. size of 15-35 nm could be prepd. by this method on polycryst. BDD film electrode, the particle size being dependent of the deposited amt. The invariant voltammetric response of the heat-treated gold deposits confirmed their applicability for electrocatalysis. [on SciFinder (R)]