Adsorption of BSA on Passivated CoCrMo PVD Alloy: An EQCM and XPS Investigation

Adsorption of Bovine Serum Albumin (BSA) on an anodically passivated CoCrMo biomedical alloy has been studied using the Electrochemical Quartz Crystal Microbalance (EQCM) in phosphate buffer solution at 37 degrees C. CoCrMo layers were deposited on the quartz crystals by physical vapor deposition. EQCM measurements were performed under potentiostatic conditions and combined with X-ray Photoelectron Spectroscopy (XPS) analysis. Adsorption of BSA onto the CoCrMo alloy surface was found to favor passive dissolution without modification of the chemical composition and thickness of the oxide passive film. In addition, passive film growth and adsorption kinetics of the protein follow a logarithmic trend. Both EQCM and XPS techniques demonstrated that protein coverage depends on the applied potential. (C) 2014 The Electrochemical Society. All rights reserved.