Study of the tribocorrosion behaviors of albumin on a cobalt-based alloy using scanning Kelvin probe force microscopy and atomic force microscopy

• Albumin can enhance the corrosion rate in static conditions for CoCrMo alloy.
• By forming a complex layer, albumin can protect the worn surface from corrosion.
• SKPFM is very useful to determine the corrosion trend of the tested biomaterials.

Once biomaterials are implanted in patients, the first reaction that occurs on the surface is the adsorption of biomolecules such as proteins, amino acids, etc. For load-bearing surfaces, some adsorbed proteins can be removed by relative motion (tribology) and some adsorbed proteins can be denatured due to tribochemical reactions. Although the effect of proteins on the corrosion behaviors of metals has been studied, the local reaction induced by the protein adsorption under tribological contact at the micro level is still unknown. The adsorption of bovine serum albumin (BSA) on CoCrMo alloy surfaces and the tribocorrosion behaviors were studied by AFM and SKPFM. The results showed that adsorbed BSA molecules could decrease the work function and promote the corrosion process for CoCrMo alloys. In the wear track, the albumin denatured, and changed the surface potential as time progressed.