Preparation and properties of bovine serum albumin thin films by pulsed laser deposition

Thin films of bovine serum albumin (BSA) were prepared by near infrared (1064 nm) pulsed laser deposition (PLD). The films comprised nanodots of 24 4 nm as primary units at laser fluence below 0.5 J cm 2. Deposition rate of BSA was determined using a quartz crystal microbalance (QCM). The film preserves primary structure of BSA, as confirmed by a matrix assisted laser desorption ionization time of flight mass spectrometer (MALDI-TOF-MS). When the fluence exceeded 10 J cm 2, we observed partial decomposition of BSAwith simultaneous change in the secondary structure of the BSA from a-helix to bsheet. Fluence dependence of the BSA structure in the deposited layer was discussed in terms of the ablation mechanisms