Analytical Sciences

Abstract − Analytical Sciences, 34(10), 1155 (2018).

Ultrasensitive Biosensor for Detection of Mercury(II) Ions Based on DNA-Cu Nanoclusters and Exonuclease III-assisted Signal Amplification
Hao ZHANG, Yanan GUAN, Xiaoshuang LI, Lili LIAN, Xiyue WANG, Wenxiu GAO, Bo ZHU, Xuying LIU, and Dawei LOU
Department of Analytical Chemistry, Jilin Institute of Chemical Technology, 45 Chengde Street, Jilin 132022, PR China
This paper describes a novel method for label-free mercury(II) ion detection based on exonuclease III-induced target signal recycling amplification using double-stranded DNA templated copper nanoclusters. The synthesized DNA-Cu nanoclusters were used with exonuclease III loop amplification technology for ultra-high sensitivity detection of mercury(II) ions, which were detected by significantly decreased fluorescence intensity. Under the optimal experimental conditions, there was a clear linear relationship between Hg2+ concentration in the range of 0.04 to 8 nM and fluorescence intensity. The detection limit for Hg2+ was 4 pM. In addition, the interference of other metal ions on the mercury(II) ion detection was also studied. To confirm the application of the fluorescent sensor, it was applied to determine the concentrations of mercury(II) ions in tap water, and the results showed that the method can be used to detect mercury(II) ions in water samples successfully.