A new piezoelectric response model for protein adsorption kinetics at a solid-liquid interface

A piezoelectric response model on the protein adsorption kinetics at a solid-liquid interface was derived. It was based on the adsorption mechanism of two consecutive reactions and the fact that the thickness-shear-mode acoustic wave sensor responses to the mass accumulation on the sensor surface during the protein adsorption. This model was used to fit the experimental data of frequency shift for the lysozyme. adsorption processes onto bare and thioglycollic acid (TGC)-modified silver electrode surfaces and those for the adsorption of bovine serum albumin (BSA) and human serum albumin (HSA) onto bare silver electrode surface. The fitted results were fairly consistent with the corresponding experimental data. The obtained regression values of rate constants, k(1) and k(2), for the lysozyme adsorption on bare silver surface were 5.93 X 10(-2) and 7.1 X 10(-4) s(-1), respectively. And those for the lysozyme adsorption on TGC-modified surface were 7.46 X 10(-2) and 1.46 X 10(-3) s(-1), respectively. The values of k(1) and k(2) for BSA adsorption on bare silver were 1.68 X 10(-2) and 4.52 X 10(-4) s(-1), and those for HSA adsorption on bare silver were 2.13 X 10(-2) and 4.06 X 10(-3) s(-1), respectively. These results exhibited the difference in adsorption kinetics for these systems. (C) 2001 Elsevier Science B.V. All rights reserved.