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 soli d-liquid interface was derived. It was based on the adsorption mechanism of two consecutive reactions and the fact that the thickness-shear-mode acous tic wave sensor responses to the mass accumulation on the sensor surface du ring the protein adsorption. This model was used to fit the experimental da ta of frequency shift for the lysozyme. adsorption processes onto bare and thioglycollic acid (TGC)-modified silver electrode surfaces and those for t he adsorption of bovine serum albumin (BSA) and human serum albumin (HSA) o nto bare silver electrode surface. The fitted results were fairly consisten t with the corresponding experimental data. The obtained regression values of rate constants, k(1) and k(2), for the lysozyme adsorption on bare silve r surface were 5.93 X 10(-2) and 7.1 X 10(-4) s(-1), respectively. And thos e for the lysozyme adsorption on TGC-modified surface were 7.46 X 10(-2) an d 1.46 X 10(-3) s(-1), respectively. The values of k(1) and k(2) for BSA ad sorption on bare silver were 1.68 X 10(-2) and 4.52 X 10(-4) s(-1), and tho se 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 ki netics for these systems. (C) 2001 Elsevier Science B.V. All rights reserve d.