Photoelectrochemical oxidation of DNA by ruthenium tris(bipyridine) on a tin oxide nanoparticle electrode

被引:100
作者
Liang, MM [1 ]
Liu, SL [1 ]
Wei, MY [1 ]
Guo, LH [1 ]
机构
[1] Chinese Acad Sci, Ecoenvironm Sci Res Ctr, State Key Lab Environm Chem & Ecotoxicol, Beijing 100085, Peoples R China
关键词
D O I
10.1021/ac051926y
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
Selective photoelectrochemical oxidation of DNA was achieved by ruthenium tris(bipyridine) immobilized on a tin oxide nanoparticle electrode. The metal complex was covalently attached to a protein, avidin, which adsorbed strongly on the tin oxide electrode by electrostatic interaction. Upon irradiation with 473-nm light, anodic photocurrent was generated in a blank electrolyte and was enhanced significantly after addition of poly(guanadylic acid) (poly-G) into the electrolyte. The current increased progressively with the nucleotide concentration, suggesting the enhancement effect was related to poly-G. The action spectrum indicates that the photocurrent was initiated by light absorption of the ruthenium compound immobilized on the electrode. Among the various polynucleotides examined, poly-G produced the largest photocurrent increase, followed by poly-A, single-stranded DNA, chemically damaged DNA, and double-stranded DNA, whereas poly-C and poly-U showed little effect. The combined experimental data support the hypothesis that the photoexcited Ru2+* species injects an electron into the semiconductor and produces Ru3+, which is then reduced back to Ru2+ by guanine and adenine bases in DNA, resulting in the recycling of the metal complex and enhanced photocurrent. The photoelectrochemical reaction can be employed as a new method for the detection of DNA damage.
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页码:621 / 623
页数:3
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