A novel graphene-DNA biosensor for selective detection of mercury ions
| Autor: | Xiaofang Zhang, Zhuobin Yuan, Yang Zhang, Ying Xue, Zhijiao Wu, Xiangjun Li, Yujian He, Hong Zhao |
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| Rok vydání: | 2013 |
| Předmět: |
Cations
Divalent Inorganic chemistry Biomedical Engineering Biophysics Oxide Biosensing Techniques Electrochemistry Coordination complex law.invention chemistry.chemical_compound Rivers Limit of Detection law A-DNA chemistry.chemical_classification Detection limit Oligonucleotide Graphene DNA Electrochemical Techniques Mercury General Medicine chemistry Graphite Biosensor Biotechnology |
| Zdroj: | Biosensors and Bioelectronics. 48:180-187 |
| ISSN: | 0956-5663 |
| DOI: | 10.1016/j.bios.2013.04.013 |
| Popis: | A novel electrochemical biosensor for sensitive and selective detection of mercury (II) ions (Hg2+) based on a DNA grafted graphene is proposed. Graphene oxide (GO) was reduced by dopamine, and then the single-strand probe DNA modified at the 5′-end with an alkylamino modifier (NH2-ssDNA) was grafted on the reduced graphene oxide (RGO) surface via Michael addition reaction. In the presence of Hg2+, the target DNA with four thymine–thymine (T–T) mismatches would hybridize with the probe DNA on the glassy carbon electrode (GCE) through T–Hg2+–T coordination chemistry. The hybridization of the two oligonucleotides leads to the increase in the peak currents of [Ru(NH3)6]3+, which could be used for electrochemical sensing of Hg2+. The difference in the value of the peak currents of [Ru(NH3)6]3+ before and after DNA hybridization was linear with the concentration of Hg2+ in the range from 8.0×10−9 to 1.0×10−7 M with a linear coefficiency of 0.996. The detection limit was 5.0×10−9 M (S/N=3). The proposed electrochemical biosensor is rapid, convenient and low-cost for effective sensing of Hg2+. Particularly, the proposed method was applied successfully to the determination of Hg2+ in real environmental samples. |
| Databáze: | OpenAIRE |
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