(355c) Biohybrid Photoelectrode Made from Photosynthetic Protein Complex Psi Entrapped within a Semi-Conducting Tcnq-Based Charge-Transfer Film

Authors: 
Bennett, T. - Presenter, University of Tennessee
Mukherjee, D., University of Tennessee
Khomami, B., University of Tennessee
Photosystem I (PSI) is a transmembrane protein which enables photoactivated charge separation with ∼1 V driving potential and ∼100% quantum efficiency during the photosynthetic process. The robust photoelectrochemical properties of PSI make it a promising candidate for harnessing solar energy. To this end, PSI has been coupled with a redox-active coordination-polymer based on the strong organic electron acceptor TCNQ in order to facilitate electron transfer in the critical step of protein–electrode charge exchange. Metal-TCNQ charge-transfer complexes have generated significant interest due to their electrical, optical, and catalytic activities. In this work, PSI is first embedded in a zinc and imidazole based MOF (ZIF-8) scaffold, which is then reacted with TCNQ to form an entrapping conductive polymer film. Subsequent immersion in aqueous electrolyte allows for electrochemically driven solid-solid conversion via cation replacement to control redox and conductive properties. Photocurrent measurements reveal significantly enhanced light-driven electron flow due to unique interfacing of PSI and polymer.