Abstract The impact of protein fouling on platinum electrodes was assessed by electrochemical methods. Protein fouling affected the electrode potential and charge transfer through the electrode-solution interface. Adsorbed proteins partially blocked the electrode, with no charge passing through blocked regions. The electrochemical theory and methodology for investigating partially blocked electrodes is fully presented, applied to protein adsorption, and the implications for bionics applications are discussed. The partially blocked electrode had a reduced admittance, and increased impedance an...