title: A regenerative ratiometric electrochemical biosensor for selective detecting Hg²⁺ based on Y-shaped/hairpin DNA transformation.
abstract: Inspired by dual-signaling ratiometric mechanism which could reduce the influence of the environmental change, a novel, convenient, and reliable method for the detection of mercury ions (Hg(2+)) based on Y-shaped DNA (Y-DNA) was developed. Firstly, the Y-DNA was formed via the simple annealing way of using two different redox probes simultaneously, omitting the multiple operation steps on the electrode. The Y-DNA was immobilized on the gold electrode surface and then an obvious ferrocene (Fc) signal and a weak methylene blue (MB) signal were observed. Upon addition of Hg(2+), the Y-DNA structure was transformed to hairpin structure based on the formation of T-Hg(2+)-T complex. During the transformation, the redox MB gets close to and the redox Fc gets far away from the electrode surface, respectively. This special design allows a reliable Hg(2+) detection with a detection range from 1 nM to 5 μM and a low detection limit down to 0.094 nM. Furthermore, this biosensor exhibits good selectivity and repeatability, and can be easily regenerated by using L-cysteine. This study offers a simple and effective method for designing ratiometric biosensors for detecting other ions and biomolecules.
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.
authors.forename: Hong Guo
authors.initials: HG
authors.lastname: Chen
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: Ji
authors.initials: J
authors.lastname: Feng
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, PR China.
authors.forename: Jing Lei
authors.initials: JL
authors.lastname: Lei
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: D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D009690:Nucleic Acid Conformation; D015203:Reproducibility of Results
chemical_list: D004247:DNA; D008628:Mercury
keywords: Mercury ion; Ratiometric biosensor; Regeneration; Square wave voltammetry; Y-shaped DNA