Application of fluorescent biosensors in the detection of Hg(II) based on T- Hg(II)-T base pairs

Abstract Mercury (II) ion (Hg2+) pollutants can accumulate in the food chain, endanger human health and harm the environment. Intelligently designed and selective methods are required for Hg2+ detection, which have been the focus of considerable research in recent years. The stabilized structure of thymine-Hg2+-thymine (T-Hg2+-T) is formed when Hg2+ combines with two thymines. Possessing convenience, high sensitivity and great selectivity, novel T-rich mercury-specific oligonucleotides (MSOs) are widely used to detect Hg2+ based on the fluorescence “turn-on/off” property of the probe molecules. In this review, the different types of fluorescence “turn-on/off” MSO probes used for the detection of Hg2+ are classified and discussed.