Silk fibroin (SF) and bovine serum albumin (BSA) thin films were deposited on Si(100) substrate either by colloid casting method or by pulsed laser deposition (PLD). Emphasis is laid on the comparison of nanostructures, which developed during the deposition. AFM diagrams were evaluated to quantify the nanostructures, parallel and perpendicular to the substrate, by the average wavelength of the profilogram (W_a) and surface roughness (R_(rms)), respectively. The film thickness increased with increasing the concentration of colloids or laser deposition time. The value of W_a increased with the film thickness. We note, however, that the value W_a becomes much less sensitive with decreasing the scanning area due to decreasing probability of the abnormally large agglomerates of the nanometric units. Probability of the agglomeration growth as a consequence of the surface adhesion is higher with higher concentration of random coil, followed by β-sheet and α-helix. BSA with smaller primary units and lower probability of agglomeration give more uniform films.
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