Modification of a Mercury Electrode with Different Thioalkanes: Structure-Sensitive Bovine Serum Albumin Analysis

Abstract

Chronopotentiometric stripping (CPS) in combination with mercury electrodes is convenient for structure-sensitive protein analysis. By using this method, we tested the discrimination between native and denatured bovine serum albumin (BSA) at various alkanethiol self-assembled monolayers (SAMs). Our results showed that alkanethiol SAMs with different headgroups or different chain lengths had different influences on the efficiency of CPS in protecting BSA from the electric field-induced denaturation. SAMs with longer alkanethiol chain lengths were more efficient in protecting BSA from denaturation at negatively charged electrode surface than those formed by short-chain alkanethiols. Short alkanethiol SAMs could be prepared by co-adsorption with the protein on the electrode surface, which was not possible with the long-chain alkanethiols. CPS data were supported by impedance analysis. We believe that our work will be useful in the electrochemical sensing of nucleic acid-protein and protein-protein binding.