Analytical Sciences

Abstract − Analytical Sciences, 20(4), 623 (2004).

Estimation of Kinetics Parameters for the Adsorption of Human Serum Albumin onto Hydroxyapatite-modified Silver Electrodes by Piezoelectric Quartz Crystal Impedance Analysis
Lu TIAN, Wan-zhi WEI, and You-an MAO
State Key Laboratory of Chemo/Biosensoring and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China
The adsorption of human serum albumin onto hydroxyapatite-modified silver electrodes has been in situ investigated by utilizing the piezoelectric quartz crystal impedance technique. The changes of equivalent circuit parameters were used to interpret the adsorption process. A kinetic model of two consecutive steps was derived to describe the process and compared with a first-order kinetic model by using residual analysis. The experimental data of frequency shift fitted to the model and kinetics parameters, k1, k2, ψ1, ψ2 and qr, were obtained. All fitted results were in reasonable agreement with the corresponding experimental results. Two adsorption constants (7.19 kJ mol-1 and 22.89 kJ mol-1) were calculated according to the Arrhenius formula.