title: Electrochemical preparation of Photosystem I-polyaniline composite films for biohybrid solar energy conversion.
abstract: In this work, we report for the first time the entrapment of the biomolecular supercomplex Photosystem I (PSI) within a conductive polymer network of polyaniline via electrochemical copolymerization. Composite polymer-protein films were prepared on gold electrodes through potentiostatic electropolymerization from a single aqueous solution containing both aniline and PSI. This study demonstrates the controllable integration of large membrane proteins into rapidly prepared composite films, the entrapment of such proteins was observed through photoelectrochemical analysis. PSI's unique function as a highly efficient biomolecular photodiode generated a significant enhancement in photocurrent generation for the PSI-loaded polyaniline films, compared to pristine polyaniline films, and dropcast PSI films. A comprehensive study was then performed to separately evaluate film thickness and PSI concentration in the initial polymerization solution and their effects on the net photocurrent of this novel material. The best performing composite films were prepared with 0.1 μM PSI in the polymerization solution and deposited to a film thickness of 185 nm, resulting in an average photocurrent density of 5.7 μA cm(-2) with an efficiency of 0.005%. This photocurrent output represents an enhancement greater than 2-fold over bare polyaniline films and 200-fold over a traditional PSI multilayer film of comparable thickness.
authors.affiliation: †Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235-1822, United States.
authors.forename: Evan A
authors.initials: EA
authors.lastname: Gizzie
authors.affiliation: †Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235-1822, United States.
authors.forename: Gabriel
authors.initials: G
authors.lastname: LeBlanc
authors.affiliation: ‡Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235-1604, United States.
authors.forename: G Kane
authors.initials: GK
authors.lastname: Jennings
authors.affiliation: †Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235-1822, United States.
authors.forename: David E
authors.initials: DE
authors.lastname: Cliffel
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D004560:Electricity; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D055668:Photochemical Processes; D045331:Photosystem I Protein Complex / Q000737:chemistry*; D058105:Polymerization; D012993:Solar Energy; D018724:Spinacia oleracea / Q000737:chemistry; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D000814:Aniline Compounds; D045331:Photosystem I Protein Complex; C416807:polyaniline
keywords: biocomposite materials; biohybrid solar cells; conjugated polymers; solar energy conversion