Fully active enzyme monolayers on electrode surfaces – Control of spatial distribution and protein orientation.
Ruhr University Bochum (RUB), Universitätstrasse 150, Bochum 44801, Germany
This lecture focusses on several challenges in self-assembled monolayers of redox enzymes on electrode material surfaces. Strategies to immobilize the enzyme in its active form will be presented first. Electrode surface functionalization with metal complexes is designed to afford a stable binding via histidine residues from the enzyme surface. The electrocatalytic enzyme activity is preserved when an electron mediator is used for the charge transfer with the electrode.
Direct electrochemistry of the redox enzyme is even more attractive for mechanistic studies, biofuel cell or biosensing applications. The direct electron transfer requires a short distance between the redox center of the enzyme and the electrode surface. Therefore, for optimized direct electron transfer, the orientation of the redox enzyme must be controlled to bring the redox center in the appropriate position with respect to the electrode surface. Our strategies involve the introduction of both natural and unnatural amino acids at the surface of the protein in the desired location for the binding site. Immobilization is achieved by affinity binding or covalent linkage.
For multiple analytes sensing, multiple biorecognition elements must be spatially separated and individually addressed. Toward SECM and electrode array based patterning applications, an electrochemically cleavable protecting group for protein anchoring sites was developed. The surface modification procedure is possible without introducing any coupling reagents and can therefore be seen as a true local patterning procedure.
In the last part, an approach to prevent oxygen interference in field application of biosensing devices will be presented.
Presentation: Keynote lecture at SMCBS'2011 International Workshop, by Nicolas Plumeré
See On-line Journal of SMCBS'2011 International Workshop
Submitted: 2011-08-31 18:13 Revised: 2011-08-31 18:13