Electric field and vibration-assisted nanomolecule desorption and anti-biofouling for biosensor applications

A novel anti-fouling mechanism based on the combined effects of electric field and shear stress is reported. A lead zirconate titanate (PZT) composite is used to generate an electric field and an acoustic streaming shear stress that increase nanomolecule desorption. In vitro characterization showed that (1) 58+/-5.5% and 39+/-5.2% of adsorbed bovine serum albumin (BSA) proteins can be effectively removed from fired silver and titanium coated PZT plate, respectively; and (2) 43+/-9.7% of the anti-mouse immunoglobulin G (IgG) can be effectively removed from a fired silver coated PZT plate. Theoretical calculations on protein-surface interactions (van der Waals (VDW), electrostatic, and hydrophobic) and shear stress describe the mechanism for protein desorption from model surfaces. We have shown that the applied electric potential is the major contributor in reducing the adhesive force between protein and surface, and the desorbed protein is taken away by acoustic streaming shear stress. We strongly believe that the present method offers the possibility of minimizing nanomolecule adsorption without further surface treatment.