title: Photocurrent generation in diamond electrodes modified with reaction centers.
abstract: Photoactive reaction centers (RCs) are protein complexes in bacteria able to convert sunlight into other forms of energy with a high quantum yield. The photostimulation of immobilized RCs on inorganic electrodes result in the generation of photocurrent that is of interest for biosolar cell applications. This paper reports on the use of novel electrodes based on functional conductive nanocrystalline diamond onto which bacterial RCs are immobilized. A three-dimensional conductive polymer scaffold grafted to the diamond electrodes enables efficient entrapment of photoreactive proteins. The electron transfer in these functional diamond electrodes is optimized through the use of a ferrocene-based electron mediator, which provides significant advantages such as a rapid electron transfer as well as high generated photocurrent. A detailed discussion of the generated photocurrent as a function of time, bias voltage, and mediators in solution unveils the mechanisms limiting the electron transfer in these functional electrodes. This work featuring diamond-based electrodes in biophotovoltaics offers general guidelines that can serve to improve the performance of similar devices based on different materials and geometries.
authors.affiliation: †Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4 Garching, 85748, Germany.
authors.forename: Roberta
authors.initials: R
authors.lastname: Caterino
authors.affiliation: †Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4 Garching, 85748, Germany.
authors.forename: Réka
authors.initials: R
authors.lastname: Csiki
authors.affiliation: †Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4 Garching, 85748, Germany.
authors.forename: Alina
authors.initials: A
authors.lastname: Lyuleeva
authors.affiliation: †Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4 Garching, 85748, Germany.
authors.forename: Jonas
authors.initials: J
authors.lastname: Pfisterer
authors.affiliation: †Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4 Garching, 85748, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Wiesinger
authors.forename: Stoffel D
authors.initials: SD
authors.lastname: Janssens
authors.forename: Ken
authors.initials: K
authors.lastname: Haenen
authors.affiliation: †Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4 Garching, 85748, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Cattani-Scholz
authors.affiliation: †Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4 Garching, 85748, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Stutzmann
authors.affiliation: †Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4 Garching, 85748, Germany.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Garrido
mesh_terms: D001674:Bioelectric Energy Sources; D004553:Electric Conductivity; D011211:Electric Power Supplies; D004566:Electrodes; D004735:Energy Transfer / Q000528:radiation effects; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008422:Materials Testing; D058612:Nanodiamonds / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D045322:Photosynthetic Reaction Center Complex Proteins / Q000502:physiology* / Q000528:radiation effects; D012993:Solar Energy
chemical_list: D058612:Nanodiamonds; D045322:Photosynthetic Reaction Center Complex Proteins
keywords: biophotovoltaics; diamonds; electron-transfer; polymer brush; reaction centers; surface functionalization