| Autor: |
Hutton, GAM, Reuillard, B, Martindale, BCM, Caputo, CA, Lockwood, CWJ, Butt, JN, Reisner, E |
| Přispěvatelé: |
Reuillard, Bertrand [0000-0002-9553-1773], Reisner, Erwin [0000-0002-7781-1616], Apollo - University of Cambridge Repository |
| Jazyk: |
angličtina |
| Rok vydání: |
2017 |
| Předmět: |
|
| DOI: |
10.17863/cam.7975 |
| Popis: |
Light-driven enzymatic catalysis is enabled by the productive coupling of a protein to a photosensitizer. Photosensitizers used in such hybrid systems are typically costly, toxic, and/or fragile, with limited chemical versatility. Carbon dots (CDs) are low-cost, nanosized light-harvesters that are attractive photosensitizers for biological systems as they are water-soluble, photostable, nontoxic, and their surface chemistry can be easily modified. We demonstrate here that CDs act as excellent light-absorbers in two semibiological photosynthetic systems utilizing either a fumarate reductase (FccA) for the solar-driven hydrogenation of fumarate to succinate or a hydrogenase (H$_{2}$ase) for reduction of protons to H$_{2}$. The tunable surface chemistry of the CDs was exploited to synthesize positively charged ammonium-terminated CDs (CD-NHMe$_{2}$$^{+}$), which were capable of transferring photoexcited electrons directly to the negatively charged enzymes with high efficiency and stability. Enzyme-based turnover numbers of 6000 mol succinate (mol FccA)$^{-1}$ and 43,000 mol H$_{2}$ (mol H$_{2}$ase)$^{-1}$ were reached after 24 h. Negatively charged carboxylate-terminated CDs (CD-CO$_{2}$$^{-}$) displayed little or no activity, and the electrostatic interactions at the CD–enzyme interface were determined to be essential to the high photocatalytic activity observed with CD-NHMe$_{2}$$^{+}$. The modular surface chemistry of CDs together with their photostability and aqueous solubility make CDs versatile photosensitizers for redox enzymes with great scope for their utilization in photobiocatalysis. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
