A reagentless DNA biosensor based on cathodic electrochemiluminescence at a C/CxO1−x electrode
| Autor: | Jian-Jun Sun, Guonan Chen, Ai-Hong Wu, Huanghao Yang, Rui-Juan Zheng |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
DNA
Complementary Luminescence Quenching (fluorescence) Surface Properties Analytical chemistry Nucleic Acid Hybridization Oxides Biosensing Techniques DNA Glassy carbon Chemistry Techniques Analytical Analytical Chemistry chemistry.chemical_compound Genetic Techniques Ferrocene chemistry Molecular beacon Electrode Electrochemistry Luminophore Electrochemiluminescence Electrodes Biosensor |
| Zdroj: | Talanta. 81:934-940 |
| ISSN: | 0039-9140 |
| Popis: | A reagentless signal-on electrochemiluminescence (ECL) biosensor for DNA hybridization detection was developed based on the quenching effect of ferrocene (Fc) on intrinsic cathodic ECL at thin oxide covered glassy carbon (C/C x O 1− x ) electrodes. To construct the DNA biosensor, molecular beacon (MB) modified with ferrocene (3′-Fc) was attached to a C/C x O 1− x electrode via the covalent bound between labeled amino (5′-NH 2 ) and surface functional groups. It was found that the immobilization of the probe on the electrode surface mainly depended on the fraction of surface carbonyl moiety. When a complementary target DNA (cDNA) was present, the stem-loop of MB on the electrode was converted into a linear double-helix configuration due to hybridization, resulting in the moving away of Fc from the electrode surface, and the restoring of the cathodic ECL signal. The restoration of the ECL intensity was linearly changed with the logarithm of cDNA concentration in the range of 1.0 × 10 −11 to 7.0 × 10 −8 M, and the detection limit was ca. 5.0 pM (S/N = 3). Additionally, single-base mismatched DNA can be effectively discriminated from the cDNA. The great advantage of the biosensor lies in its simplicity and cost-effective with ECL generated from the electrode itself, and no adscititious luminophore is required. |
| Databáze: | OpenAIRE |
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