Mechanical vibration-assisted modulation of E. coli binding to poly-l-lysine coated biosensor surface

We show for the first time that intensity of transverse vibration of a surface modulates binding and unbinding of Escherichia coli JM101 (negatively charged) from a poly-l-lysine (PLL; positively charged) coated surface. Excitation voltage of a piezoelectric-excited millimeter-sized cantilever (PEMC) sensor, when increased from 0.1 to 1 V, its displacement magnitude and surface acceleration increases by 10-fold which caused decreased E. coli attachment on the PLL-coated surface as measured by scanning electron microscope. A flow configuration, designed for ensuring identical experimental conditions for both test (with vibration) and control (without vibration) surfaces, was used in examining the effects of surface vibration on binding and unbinding. Increase of surface vibration intensity was effective in reducing E. coli attachment to the PLL-coated surface. In a similar vein, removal of pre-attached E. coli cells increased with increased vibration intensity and time of vibration used.