Albumin adsorption on alkanethiols self-assembled monolayers on gold electrodes studied by chronopotentiometry

Abstract

Chronopotentiometry was used to study the adsorption of human serum albumin (HSA) to self-assembled monolayers with the following terminal functional groups: CH 3, COOH and OH. Surfaces were characterized by X-ray photoelectron spectroscopy, water contact angle measurements and cyclic voltammetry. HSA coverage of the different SAMs was investigated by chronopotentiometry and the total amount of adsorbed protein was determined using radiolabelled albumin. Both techniques have demonstrated that HSA adsorption to the different SAM-modified electrodes increases in the following order: OH<COOH<CH 3-terminated SAMs. A good correlation between coverage and total amount of HSA adsorbed was observed for long adsorption times (900 s).