In Situ AFM Investigation On The Immobilization Technology Of Nano Biosensors

Protein Adsorption is of great importance for the immobilization of biosensors. The self-assembly adsorption of functional protein upon nano crystal surface, as a crucial phenomenon, broadly takes place at many applications including biosensors, bio-capsules and bio-MEMS/bio-NEMS. To investigate interaction trait systematically, a hybrid surface composing silica and discontinuous Gold Nano Film (GNF) was fabricated by Physical Vapor Deposition (PVD) and ultrasonic cleaning technology, and the self-assembly adsorption of Bovine Serum Albumin (BSA) upon the hybrid surface was in situ characterized by Atomic Force Microscope (AFM).The variations on the junction area between the two different crystals in aqueous solution were focused before and after injecting BSA with 0.05mg/ml concentration. It was found that silica, compared with same hydrophilic GNF, took on fairly weak adsorption force. The results could indicate that the adsorption strength of BSA on the hydrophilic crystal surface is determined not only by hydrophilic property, but other interaction forces, like Van Der Waals and so on. Moreover, observed under the contact mode of AFM, BSA adsorbed on GNF had great tendency to forming a ridge-like topography. These results may further facilitate the recognizing of adsorption mechanism of BSA upon the hybrid crystal surface concerned with immunosensors and other areas.