A highly sensitive label-free sensor for Mercury ion (Hg2+) by inhibiting thioflavin T as DNA G-quadruplexes fluorescent inducer

With the addition of thioflavin T (ThT), the G-rich DNA sequences can fold into quadruplex structures resulting in high florescence intensity of ThT. Because Hg2+ can specifically transform DNA G-quadruplexes to duplex nucleic acid structures, the fluorescence intensity of ThT will be reduced. Therefore, we can use ThT to detect Hg2+. This Hg2+ biosensor will provide a versatile tool for the detection of Hg2+ in environmental samples and Hg2+ bioactivity analysis.