Electron Transfer Mechanisms in Nanomaterials-Incorporated Metalloprotein-Films on Electrodes

The contribution of nanomaterials in developing modern ultrasensitive biosensors and biocatalytic systems is immense. Our focus has particularly been on understanding the fundamental electrochemical properties of redox-protein films immobilized on nanostructured electrodes or incorporated with redox-mediating nanomaterials. In the first approach, we designed non-covalently functionalized carbon nanotube modified electrodes with different pyrene derivatives, via the strong π-π stacking, to achieve directed attachment of myoglobin protein or site-specific attachment of small peroxidase-active microperoxidase-11. Direct electron transfer and catalytic properties of covalent versus electrostatic methods of immobilizing protein films and the effect of electrode materials will be discussed.

     Our second approach is based on conjugating redox-proteins with magnetic nanomaterials to immobilize on polymer coated electrodes and understand the direct electrochemical properties. Our results provide insights with regard to the direct electron transfer rates, catalytic efficiency, biological long-range electron hopping, and through-bond coupled hopping mechanism on the investigated nanomaterial-redox protein electrodes. We envisage that our findings will aid in designing viable, scalable bioreactors for green synthesis, superior biosensors, and understanding the biological electron transfer processes.

Acknowledgements. Financial support by Oklahoma State University is greatly acknowledged.