[Ru(bpy) 2 dppz] 2+ Electrochemiluminescence Switch and Its Applications for DNA Interaction Study and Label-free ATP Aptasensor
2009; American Chemical Society; Volume: 81; Issue: 23 Linguagem: Inglês
10.1021/ac901925x
ISSN1520-6882
AutoresLianzhe Hu, Zheng Bian, Haijuan Li, Shuang Han, Yali Yuan, Lianxun Gao, Guobao Xu,
Tópico(s)Molecular Junctions and Nanostructures
Resumo[Ru(bpy)2dppz]2+ electrochemiluminescence (ECL) was studied, and it was used to investigate DNA interaction and develop a label-free ATP aptasensor for the first time. ECL of [Ru(bpy)2dppz]2+ is negligible in aqueous solution, and increases approximately 1000 times when [Ru(bpy)2dppz]2+ intercalates into the nucleic acid structure. The ECL switch behavior of [Ru(bpy)2dppz]2+ is ascribed to the intercalation that shields the phenazine nitrogens from the solvent and results in a luminescent excited state. The ECL switch by DNA was applied to investigate the interaction of [Ru(bpy)2dppz]2+ with herring sperm DNA. The calculated equilibrium constant (K) is 1.35 x 10(6) M(-1), and the calculated binding-site size (s) is 0.88 base pair, which is consistent with the reported values. Moreover, ATP can dramatically affect ECL of the [Ru(bpy)2dppz]2+/ATP aptamer complex. As a result, a label-free, sensitive, and selective [Ru(bpy)2dppz]2+ ECL method for ATP detection was developed. The detection limit is 100 nM for ATP (with a signal-to-noise ratio, S/N, of 3) with a linear range of 0-1 microM. The result demonstrates that [Ru(bpy)2dppz]2+ ECL holds great promise in aptasensors.
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