Highly sensitive fluorescence detection of mercury (II) ions based on DNA machine amplification

We report a highly sensitive fluorescence detection method of Hg2+ ions in aqueous solution, which is based on strong and stable T–Hg2+–T coordination chemistry and DNA machine signal amplification. Under the optimum conditions, a good linear relationship with the concentration of Hg2+ ion from 1.0 × 10−8 M to 1.0 × 10−6 M and detection limits as low as 2.2 × 10−9 M (3σ) are achieved. As a promising biomolecular device, this DNA machine may have an even broader application in the rapidly developing field of nano-biotechnology for other metal ions detection.