Quantum chemical study of TiO{sub 2}/dopamine-DNA triads.
Photoinduced charge separation in triads of DNA covalently linked to an anatase nanoparticle via a dopamine bridge was studied by ab initio calculations of the oxidation potentials of carboxyl-DNA trimers and the TiO2/dopamine complex. Conjugation of dopamine to the TiO2 surface results in a lower oxidation potential of the complex relative to the surface and in localization of photogenerated holes on dopamine, while photogenerated electrons are excited into the conduction band of TiO2. Linking dopamine to the DNA trimers at the 5? end of the oligonucleotide may lead to further hole migration to the DNA. Calculations show that for several different sequences hole migration is favorable in double stranded DNA and unfavorable in single-stranded DNA. This extended charge separation was shown to follow from the redox properties of DNA sequence rather than from the modification of DNA's electron donating properties by the dopamine linker, which explains experimental observations.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- SC
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 920555
- Report Number(s):
- ANL/MSD/JA-55057
- Journal Information:
- Chem. Phys., Journal Name: Chem. Phys. Journal Issue: 1-3 ; Oct, 15, 2007 Vol. 339; ISSN CMPHC2; ISSN 0301-0104
- Country of Publication:
- United States
- Language:
- ENGLISH
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