文献类型：期刊文献

英文题名：A Sensitive Fluorescence Biosensor for Silver Ions (Ag⁺) Detection Based on C-Ag⁺-C Structure and Exonuclease III-Assisted Dual-Recycling Amplification

作者：Li, Yubin[1];Yuan, Jiaming[1];Xu, Zexi[2]

机构：[1]Guangdong Ocean Univ, Sch Chem & Environm, Zhanjiang 524088, Peoples R China;[2]Univ Leeds, Sch Food Sci & Nutr, Leeds LS2 9JT, W Yorkshire, England

年份：2019

卷号：2019

外文期刊名：JOURNAL OF ANALYTICAL METHODS IN CHEMISTRY

收录：SCI-EXPANDED(收录号：WOS:000461660600001)、、WOS

基金：This work was supported by the Innovation Strong School Project of Guangdong Education Department (no. Q18291), the Nonfunded Scientific and Technological Research Projects in Zhanjiang City (no. 2018B01005), and the Program for Scientific Research Start-Up Funds of Guangdong Ocean University (no. R17013).

语种：英文

外文摘要：A C-Ag+-C structure-based fluorescence biosensor with novel combination design of exonuclease III (Exo III) dual-recycling amplification is proposed for the application of silver ions (Ag+) detection. Since oligo-1 involves C-C mismatches, the presence of Ag+ can be captured to form C-Ag+-C base pairs, which results in a double-helix structure with a blunt terminus. The double-helix structure can be cleaved by EXO III to release short mononucleotide fragments (trigger DNA) and Ag+. Released Ag+ can form new bindings with oligo-1, and other trigger DNA can be produced in the digestion cycles. Hybridization with the signal DNA (oligo-2) transforms a trigger DNA into double-stranded DNA with blunt terminus which can be cleaved by Exo III to reproduce the trigger DNA and form guanine- (G-) quadruplex DNA. The trigger DNA returns free to the solution and hybridizes with another signal DNA, which realizes the dual-recycling amplification. The G-quadruplex DNA can be reported by N-methylmesoporphyrin IX (NMM), a specific G-quadruplex DNA fluorochrome. This method allows Ag+ to be determined in the 5 to 1500pmol/L concentration range, with a 2pmol/L detection limit, and it has been successfully applied to the detection of Ag+ in real samples.