Quartz Resonator for Simultaneous Measurement of Changes in Mass and Electrical Impedance during Protein Adsorption

Abstract

A novel quartz resonator has been developed for the synchronized measurement of changes in mass and electrical impedance during the adsorption of various concentrations of bovine serum albumin (BSA). The top platinum surface of the quartz crystal was used as the working electrode and real-time Fourier transform analysis was conducted to obtain time-resolved electrochemical impedance spectra. The change in mass due to the BSA adsorption was calculated from the change in the frequency of the quartz resonator. These simultaneous measurements of mass and electrical impedance were used to determine not only the kinetics of protein adsorption but also the morphological changes in the adsorbed layer, which were confirmed with atomic force microscopy. (C) 2013 The Electrochemical Society. All rights reserved.