Abstract |
We report photocatalytic H(2) production by hydrogenase (H(2)ase)-quantum dot (QD) hybrid assemblies. Quenching of the CdTe exciton emission was observed, consistent with electron transfer from the quantum dot to H(2)ase. GC analysis showed light-driven H(2) production in the presence of a sacrificial electron donor with an efficiency of 4%, which is likely a lower limit for these hybrid systems. FTIR spectroscopy was employed for direct observation of active-site reduction in unprecedented detail for photodriven H(2)ase catalysis with sensitivity toward both H(2)ase and the sacrificial electron donor. Photosensitization with Ru(bpy)(3)(2+) showed distinct FTIR photoreduction properties, generating all of the states along the steady-state catalytic cycle with minimal H(2) production, indicating slow, sequential one-electron reduction steps. Comparing the H(2)ase activity and FTIR results for the two systems showed that QDs bind more efficiently for electron transfer and that the final enzyme state is different for the two sensitizers. The possible origins of these differences and their implications for the enzymatic mechanism are discussed.
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Authors | Brandon L Greene, Crisjoe A Joseph, Michael J Maroney, R Brian Dyer |
Journal | Journal of the American Chemical Society
(J Am Chem Soc)
Vol. 134
Issue 27
Pg. 11108-11
(Jul 11 2012)
ISSN: 1520-5126 [Electronic] United States |
PMID | 22716776
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Cadmium Compounds
- Hydrogen
- 3-Mercaptopropionic Acid
- Hydrogenase
- Tellurium
- cadmium telluride
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Topics |
- 3-Mercaptopropionic Acid
(chemistry)
- Cadmium Compounds
(chemistry)
- Catalysis
- Catalytic Domain
- Electron Transport
- Hydrogen
(metabolism)
- Hydrogenase
(chemistry, metabolism)
- Light
- Models, Molecular
- Oxidation-Reduction
- Photochemical Processes
- Quantum Dots
- Tellurium
(chemistry)
- Thiocapsa roseopersicina
(enzymology)
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