title: A novel strategy for dual-channel detection of metallothioneins and mercury based on the conformational switching of functional chimera aptamer.
abstract: A novel strategy for dual-channel detection of metallothioneins (MTs) and Hg(2+) has been proposed. In the absence of Hg(2+), the functional chimera aptamer (FCA) designed can form an intact G-quadruplex with flexibility, which was demonstrated to have peroxidase-like activities upon hemin binding. In the presence of Hg(2+), the formation of T-Hg(2+)-T complex results in the conformational switching of FCA, which lost the peroxidase-like activities and cannot catalyze the oxidation of ABTS by H2O2. Upon addition of MTs in this solution, MTs could interact with Hg(2+) to form a MTs-Hg(2+) complex, leading to the recovery of the G-quadruplex DNAzyme. The color and absorbance of the sensing system were also changed accordingly. In the optimizing condition, ΔA was directly proportional to the concentration ranging from 8.84 nM to 1.0 μM for Hg(2+), and 7.82 nM to 0.462 μM for MTs with the detection limits of 2.65 nM and 2.34 nM, respectively. The proposed dual-channel method avoids the label steps in common methods, and allows direct analysis of the samples without costly instruments, and is reliable, inexpensive and sensitive.
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Xian
authors.initials: X
authors.lastname: Tang
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China. Electronic address: yongsheng.w@tom.com.
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Wang
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Xue
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Jin-Xiu
authors.initials: JX
authors.lastname: Cao
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Si-Han
authors.initials: SH
authors.lastname: Chen
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Li
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Wang
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Zhu
authors.affiliation: College of Public Health, University of South China, Hengyang 421001, PR China.
authors.forename: Yan-Qin
authors.initials: YQ
authors.lastname: Huang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D002678:Chimera; D003124:Colorimetry / Q000379:methods; D021881:DNA, Catalytic / Q000737:chemistry; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D008628:Mercury / Q000737:chemistry*; D008668:Metallothionein / Q000737:chemistry*; D008968:Molecular Conformation; D010084:Oxidation-Reduction
chemical_list: D021881:DNA, Catalytic; D006427:Hemin; D008668:Metallothionein; D006861:Hydrogen Peroxide; D008628:Mercury
keywords: Conformational switching; Dual-channel; Functional chimera aptamer; Mercury; Metallothioneins