We apply the ex situ and in situ atomic force microscopy (AFM) nanoshaving technique to investigate the bovine serum albumin (BSA) films on Au(111) and highly oriented pyrolytic graphite (HOPG) surfaces. The both substrates were found to support the BSA films.
The section analysis performed before and after the AFM nanoshaving allowed the determination of the film thickness. On Au(111) surface, both ex situ and in situ nanoshaving revealed that the film is formed by strongly denatured BSA molecules, with the average thickness 2.3 +/- 0.2 and 2.0 +/- 0.2 nm, respectively.
On the other hand, the HOPG substrate was found to support less denatured BSA films, with the average film thickness 4.7 +/- 0.3 and 5.2 +/- 0.3 nm, based on the ex situ and in situ measurements, respectively.