文献类型：期刊文献

英文题名：Label-free colorimetric detection of divalent mercuric ions (Hg2+) based on T-Hg2+-T structure and exonuclease III dual-recycling and G-quadruplex-hemin DNAzyme amplification

作者：Yuan, Jiaming[1]; Wu, Yulian[1]; Kang, Xinhuang[1]; Liu, Huazhong[1]; Li, Yubin[1]

机构：[1] School of Chemistry and Environment, Guangdong Ocean University, Zhanjiang, China

年份：2020

卷号：100

期号：8

起止页码：841

外文期刊名：International Journal of Environmental Analytical Chemistry

收录：EI(收录号：20193207268052)、Scopus(收录号：2-s2.0-85086636124)

语种：英文

外文关键词：Recycling - Color - Mercury compounds - DNA - Colorimetry

外文摘要：Detection of divalent mercury attracts great significance in most biological and environmental systems. In this study, a Thymine-divalent mercuric ions-Thymine (T-Hg2+-T) structure based colorimetric assay with Exonuclease III (Exo III) assisted recycling and G-quadruplex-hemin DNAzyme amplification is put forward for Hg2+ monitoring. The Hg2+ can combine with T-T mismatches of oligo-1 to form T-Hg2+-T base pairs, which brings forth a double-helix structure with a blunt terminus. Short mononucleotide fragment (trigger DNA) and Hg2+ could be released as the double-helix structure in oligo-1 is cleaved by Exo III. The released Hg2+ can be captured by another oligo-1, and generate the new cycles. At the same time, signal DNA (oligo-2) can hybridize with trigger DNA to form double-stranded DNA with a blunt terminus that can be cleaved by Exo III to accrue the trigger DNA and guanine (G)-quadruplex fragment. The trigger DNA can hybridize with another signal DNA, which implements the dual-recycling amplification. The G-quadruplex fragment can form the G-quadruplex-hemin DNAzymes, which can catalyze the oxidation of 2, 2?-azino-bis(3-ethylbenzothiazo-line-6-sulfonate) disodium salt (ABTS2-) by H2O2. The color change, served as the signal output, can be measured with an ultraviolet spectrophotometer. The proposed assay allows Hg2+ to be detected in the range of 25 pM to 2000 pM with a detection limit of 7 pM. Moreover, it has been commendably applied to the determination of Hg2+ in environmental samples and biological samples. ? 2019, ? 2019 Informa UK Limited, trading as Taylor & Francis Group.