A homogeneous electrochemical sensor for Hg2+ determination in environmental water based on the T–Hg2+–T structure and exonuclease III-assisted recycling amplification. Issue 9 (12th April 2018)

• Record Type: Journal Article
• Authors: Fu, Caili; Yu, Hao; Su, Lingshan; Liu, Chang; Song, Yanling; Wang, Shaoyun; Lin, Zhenyu; Chen, Fang
• Is Part Of: Analyst. Volume 143:Issue 9(2018)
• Page Start: 2122
• Page End: 2127
• Publication Date: 2018-04-12
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/c8an00462e
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : A simple, fast, sensitive, and homogeneous electrochemical sensor based on the T–Hg 2+ –T structure and exonuclease III-assisted recycling amplification has been constructed for mercury ion (Hg 2+ ) detection. Abstract : A simple, fast, sensitive, and homogeneous electrochemical sensor based on the T–Hg 2+ –T structure and exonuclease III-assisted recycling amplification has been constructed for mercury ion (Hg 2+ ) detection. The cT and methylene blue-labeled DNA probes (MB-TDNA) were designed to contain poly T sequences, which were repulsed from the negatively charged indium tin oxide (ITO) electrode due to their abundant negative charges. Hg 2+ could trigger the formation of double-stranded DNA (dsDNA) between two DNA probes owing to the stable T–Hg 2+ –T structure. Then, Exo III specifically recognizes the cleavage of the double-stranded structure to release a methylene blue-labeled mononucleotide fragment (MB-MF). Moreover, the release of the target Hg 2+ induces new hybridization and produces a large number of MB-MFs; MB-MFs are not repulsed by the negatively charged ITO electrode surface, thus producing a significant current signal. Under optimal conditions, the differential pulse voltammetric (DPV) response had a linear relationship with the logarithm of Hg 2+ concentration in the range of 1.0 nM–0.5 μM, and the proposed method displayed great applicability for detecting Hg 2+ in tap-water samples.