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Photoelectron Generation by Photosystem II Core Complexes Tethered to Gold Surfaces
Author(s) -
Vittadello Michele,
Gorbunov Maxim Y.,
Mastrogiovanni Daniel T.,
Wielunski Leszek S.,
Garfunkel Eric L.,
Guerrero Fernando,
Kirilovsky Diana,
Sugiura Miwa,
Rutherford A. William,
Safari Ahmad,
Falkowski Paul G.
Publication year - 2010
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.200900255
Subject(s) - x ray photoelectron spectroscopy , monolayer , chemistry , electron transfer , acceptor , materials science , analytical chemistry (journal) , chemical physics , photochemistry , nanotechnology , physics , nuclear magnetic resonance , condensed matter physics , chromatography
By using a nondestructive, ultrasensitive, fluorescence kinetic technique, we measure in situ the photochemical energy conversion efficiency and electron transfer kinetics on the acceptor side of histidine‐tagged photosystem II core complexes tethered to gold surfaces. Atomic force microscopy images coupled with Rutherford backscattering spectroscopy measurements further allow us to assess the quality, number of layers, and surface density of the reaction center films. Based on these measurements, we calculate that the theoretical photoelectronic current density available for an ideal monolayer of core complexes is 43 μA cm −2 at a photon flux density of 2000 μmol quanta m −2 s −1 between 365 and 750 nm. While this current density is approximately two orders of magnitude lower than the best organic photovoltaic cells (for an equivalent area), it provides an indication for future improvement strategies. The efficiency could be improved by increasing the optical cross section, by tuning the electron transfer physics between the core complexes and the metal surface, and by developing a multilayer structure, thereby making biomimetic photoelectron devices for hydrogen generation and chemical sensing more viable.