title: A novel label-free and sensitive electrochemical biosensor for Hg2+based on ligase-mediated formation of DNAzyme.
abstract: A novel label-free electrochemical biosensor for the detection of Hg2+based on ligase mediated creation of G-quadruplex-hemin DNAzyme has been developed. Firstly, Cp probe was immobilized on the gold electrode surface through Au-SH bond. In the presence of Hg2+, Cp and Ap probes were partly hybridized with the LJ probe respectively through the specific T-Hg2+-T interaction. Then, the adjacent 3'-OH terminal of Cp will link with the 5'-PO4terminal of Ap to form a G-rich DNA at the function of T4-ligase. After interaction with hemin, the G-rich DNA can form a G-quadruplex-hemin HRP-mimicking DNAzyme. Through measuring the current change caused by DNAzyme-catalyzed oxidation of 3,3',5,5'-tetramethylbenzidine(TMB), sensitive detection of Hg2+can be achieved. The proposed sensor is simple, sensitive and selective, without the need of complicated labeling process, thus holds great potential for routine analysis of Hg2+in environmental and biological samples.
authors: Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou, Fujian 350108, China.
authors: Guangwen
authors: G
authors: Li
authors: Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou, Fujian 350108, China.
authors: Zhijun
authors: Z
authors: Li
authors: Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou, Fujian 350108, China.
authors: Xiuhua
authors: X
authors: You
authors: Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou, Fujian 350108, China. Electronic address: cjh_huaxue@126.com.
authors: Jinghua
authors: J
authors: Chen
authors: Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou, Fujian 350108, China. Electronic address: srtang@fjmu.edu.cn.
authors: Shurong
authors: S
authors: Tang
mesh_terms: D001560:Benzidines / Q000737:chemistry; D015374:Biosensing Techniques; D015342:DNA Probes; D021881:DNA, Catalytic / Q000737:chemistry*; D060766:Drinking Water / Q000032:analysis; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006427:Hemin / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008025:Ligases / Q000737:chemistry; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D001560:Benzidines; D015342:DNA Probes; D021881:DNA, Catalytic; D060766:Drinking Water; D006046:Gold; D006427:Hemin; D006861:Hydrogen Peroxide; D008025:Ligases; D008628:Mercury; D062065:Wastewater; D014874:Water Pollutants, Chemical; C021758:3,3',5,5'-tetramethylbenzidine
keywords: DNAzyme; Electrochemical biosensor; Hg(2+) detection; Label-free