Gold nanoparticles covered by derivatives of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) with well-defined coverage and narrow size distribution were synthesized and self-assembled on the gold electrode. The TEMPO nanoparticle-coated electrode was characterized using STM and AFM. The kinetics of oxidation of the nitroxide radicals attached to the nanoparticles was evaluated based on cyclic voltammetry measurements. The TEMPO–nanoparticle modified electrode was found more efficient in electrocatalytic oxidation of benzyl alcohol than the electrode modified with a monolayer of TEMPO molecules directly bound to the gold surface.