PROTEIN ADSORPTION AT GLASSY-CARBON ELECTRODES - THE EFFECT OF COVALENTLY BOUND SURFACE GROUPS

A diazonium salt coupling procedure was used to covalently bind various-p-substituted phenyls to glassy carbon electrodes. The response of modified electrodes for oxidation of ferrocenemethanol in the absence and presence of bovine serum albumin was monitored to give a measure of protein adsorption. Carboxylate groups close to the surface did not influence protein adsorption (relative to polished glassy carbon electrodes), however, hydrophobic groups increased adsorption. These results are compared to those for similar experiments at electrochemically pretreated glassy carbon electrodes. Hydrophilic groups attached to the surface via sufficiently long linkages reduced protein adsorption and may be useful for analysis of clinical samples.