Electrochemical Study of a Laser Marked Biomaterial in Albumin Solution

Proteins are widely used in solutions in order to simulate the physiological fluids and study corrosion mechanisms. The present work appraised the ASTM F 139 austenitic stainless steel (SS), employed in prostheses manufacture, and engraved by a nanosecond laser beam, using a phosphate buffered solution with 10 g/L of bovine serum albumin (PBS + BSA). Due to the complexity of the interaction between protein and the biomaterial, it was necessary to use higher BSA concentrations, however, similar to those found in human serum. The electrochemical tests consisted in monitoring the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and cyclic polarisation measurements. The results showed that the laser marked areas are more susceptible to corrosion; suggesting that the laser marking technique has a more preponderant effect on the passive film protective character than the albumin addition to the electrolyte.