Mercury–DNA interaction based detection of mercury ions by DNA amplification with high sensitivity and selectivity

An effective and facile approach for mercury detection is essential for environmental protection and human health. In this study, we propose a novel strategy to develop a highly sensitive and selective method for the detection of mercury ions using real-time quantitative polymerase chain reaction (RT-qPCR) technology and the specific binding of Hg2+ in thymine–thymine mismatch complexes. The signal for detection of Hg2+ was generated using RT-qPCR amplification of a template strand of DNA. The sensor exhibited an excellent linear response between the cycle threshold (Ct) and mercury ion concentration in the range of 0.05–100 nM. Under optimised conditions, the detection limit of this method for aqueous Hg2+ was as low as 30 pM. In addition, this system showed good selectivity for Hg2+ over other metal ions. This new approach shows significant potential for detection of Hg2+ in water and other samples.