Highly Sensitive and Selective Detection of Hg2+ in Aqueous Solution with Mercury-specific DNA and SYBR GREEN I

Abstract

Abstract:

A novel “signal-on” assay for sensitive and selective detection of Hg2+ in aqueous solution based on mercury-specific DNA and a molecular light switch complex, SYBR GREEN I, was reported in the present work. This Hg²⁺ specific sensor system composed of two labelfree DNA probes with five T-T mis-matches, which could form stable DNA duplexes by thymine-Hg²⁺-thymine（T-Hg²⁺-T）in the presence of Hg²⁺. The fluorescence of SYBR GREEN I is weak in aqueous solution, and significant fluorescence can be observed when intercalating into DNA duplexes. By monitoring Hg²⁺-dependent fluorescence intensity enhancement, highly sensitive and selective determination of Hg²⁺ has been achieved. Under the optimum conditions, the fluorescence intensity was proportional to the concentration of Hg²⁺ in the range of 5-100 nmol/L. A detection limit of 2 nmol/L Hg²⁺ was achieved. The presence of other metal ions did not interfere with the detection of Hg²⁺. This approach is simple and rapid, which can be used to monitor the Hg²⁺ concentration in drinking water.

Key words: Hg²⁺, DNA probe, Fluorimetry, SYBR GREEN I

Wu Jikui, Wei Biwen, Lin Li, Mao Fang, Zhou Dongxiang, Xiong Zhenhai. Highly Sensitive and Selective Detection of Hg2+ in Aqueous Solution with Mercury-specific DNA and SYBR GREEN I[J]. Biotechnology Bulletin, 2013, 0(4): 221-224.

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