title: A label-free electrochemical sensor for detection of mercury(II) ions based on the direct growth of guanine nanowire.
abstract: A simple, sensitive and label-free electrochemical sensor is developed for detection of Hg(2+) based on the strong and stable T-Hg(2+)-T mismatches. In the presence of Mg(2+), the parallel G-quadruplex structures could be specifically recognized and precipitated in parallel conformation. Therefore, the guanine nanowire was generated on the electrode surface, triggering the electrochemical H2O2-mediated oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). In this research, a new method of signal amplification for the quantitative detection of Hg(2+) was described based on the direct growth of guanine nanowire via guanine nanowire. Under optimum conditions, Hg(2+) was detected in the range of 100 pM-100 nM, and the detection limit is 33 pM. Compared to the traditional single G-quadruplex label unit, this electrochemical sensor showed high sensitivity and selectivity for detecting Hg(2+).
authors.affiliation: Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Yan Li
authors.initials: YL
authors.lastname: Huang
authors.affiliation: Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Zhong Feng
authors.initials: ZF
authors.lastname: Gao
authors.affiliation: Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Jia
authors.affiliation: Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: luohq@swu.edu.cn.
authors.forename: Hong Qun
authors.initials: HQ
authors.lastname: Luo
authors.affiliation: Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: linb@swu.edu.cn.
authors.forename: Nian Bing
authors.initials: NB
authors.lastname: Li
mesh_terms: D001560:Benzidines / Q000737:chemistry; D015374:Biosensing Techniques; D060766:Drinking Water / Q000032:analysis / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D054856:G-Quadruplexes; D006046:Gold / Q000737:chemistry; D006147:Guanine / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D053770:Nanowires / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D001560:Benzidines; D060766:Drinking Water; D014874:Water Pollutants, Chemical; C021758:3,3',5,5'-tetramethylbenzidine; D006147:Guanine; D006046:Gold; D006861:Hydrogen Peroxide; D008628:Mercury
keywords: Electrochemical sensor; Guanine nanowire; Hg(2+)