Bioconjugated nanoparticles that combine the selectivity of biomolecules with the unique properties of nanoparticles have received a great deal of interest for applications in biomedicine, biosensing and biotechnology. While widely used, evaluation and characterization of immobilized biomolecules on the surface of nanoparticles remain a challenge. In this presentation, we describe the use of nano-impact electrochemistry as a novel technique for characterizing biomolecule-nanoparticle conjugation. The method can be used to quantitatively investigate biomolecular recognition and bioconjugation with a high degree of sensitivity and in the absence of exogenous reagents.