Investigation of the kinetics of macromolecule adsorption by means of the quartz microbalance and double-layer capacitance measurement: Application to the adsorption of bovine serum albumin onto gold electrode
✍ Scribed by F. Lacour; R. Torresr; C. Gabrielli; A. Caprani
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 680 KB
- Volume
- 1
- Category
- Article
- ISSN
- 0927-7765
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✦ Synopsis
The time variattons of the double layer capacitance and of the oscillation frequency of an electrochemical quartz microbalance are simultaneously recorded to determine the kmetics of adsorption of bovine serum albumin on a gold electrode. Both variations which can be fitted by a sum of exponential functions corroborate a consecutive irreversible step model already proposed. It IS estabhshed that for the steps assoctated with a mass change both methods provide the same values for the time constants This result validates the double-layer capacitance measurement method (which IS indirect) as a tool for determining m situ the kmetics of protem adsorption In addition to the information common to the two methods, these methods provide complementary mformatton: number of adsorbed monolayers for the quartz microbalance; change of the layer structure at constant thickness for the double layer capacitance.
Thus. according to the sign of the electrical charge of the interface, two or three monolayers are adsorbed end-on durmg the adsorption process. Finally. it is estabhshed that m our conditions the quartz oscillation modifies with respect to the non-oscillating quartz, the kinetics of adsorption and the structure of the adsorbed layer