Influences of properties of protein and adsorption surface on removal kinetics of protein adsorbed on metal surface by H₂O₂-electrolysis treatment

"H₂O₂-electrolysis" treatment is an alternative method for removing proteinaceous materials that are adsorbed to metal surfaces. The method is based on the generation of hydroxyl radicals by electrolysis of hydrogen peroxide and the subsequent decomposition of organic substances adhering to the metal surface. We herein investigated the influence of some parameters on the kinetics of protein removal by H₂O₂-electrolysis. These parameters included the properties of proteins and the type of metal surface. Sixteen types of proteins and nine types of metal surfaces were used. The removal of adsorbed protein from a metal surface during the treatment was monitored by ellipsometry. Apparent first-order rate constants for removal, k_cl, for various adsorption and treatment conditions were determined. The k_cl value varied markedly with the type of protein and was also influenced by the pH used in the adsorption. The isoelectric point (pI) of protein used was found to be a major factor. The amount of adsorbed protein removed by a unit amount of OH was larger for a metal surface with a lower pI. The impact of the properties of the protein and metal surface on the removal kinetics are discussed, focusing on relationships with the adsorption characteristics of the protein.