title: Dual-channel detection of metallothioneins and mercury based on a mercury-mediated aptamer beacon using thymidine-mercury-thymidine complex as a quencher.
abstract: A novel dual-channel strategy for the detection of metallothioneins (MTs) and Hg(2+) has been developed based on a mercury-mediated aptamer beacon (MAB) using thymidine-mercury-thymidine complex as a quencher for the first time. In the presence of Hg(2+), the T-rich oligonucleotide with a 6-carboxyfluorescein (TRO-FAM) can form an aptamer beacon via the formation of T-Hg(2+)-T base pairs, which results in a fluorescence quenching of the sensing system owing to the fluorescence resonance energy transfer (FRET) from the fluorophore of FAM to the terminated T-Hg(2+)-T base pair. The addition of MTs into this solution leads to the disruption of the T-Hg(2+)-T complex, resulting in an increase of the fluorescent signal of the system. In the optimizing condition, ΔF was directly proportional to the concentrations ranging from 5.63 nM to 0.275 μM for MTs, and 14.2 nM to 0.30 μM for Hg(2+) with the detection limits of 1.69 nM and 4.28 nM, respectively. The proposed dual-channel method avoids the label steps of a quencher in common molecular beacon strategies, without tedious procedure or the requirement of sophisticated equipment, and is rapid, inexpensive and sensitive.
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. 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: Yun-Sheng
authors.initials: YS
authors.lastname: Chen
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.
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: 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: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry; D008628:Mercury / Q000032:analysis* / Q000737:chemistry*; D008668:Metallothionein / Q000032:analysis*; D015335:Molecular Probes; D013050:Spectrometry, Fluorescence; D013936:Thymidine / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D005456:Fluorescent Dyes; D015335:Molecular Probes; D008668:Metallothionein; D008628:Mercury; D013936:Thymidine
keywords: Dual-channel; Mercury; Mercury-mediated aptamer beacon; Metallothioneins; Thymidine–mercury–thymidine quencher