Fluorescent detection of Hg2+ and Pb2+ using GeneFinder™ and an integrated functional nucleic acid

This paper reports a simple fluorescent assay for the determination of Hg(2+) and Pb(2+) by using a DNA intercalator GeneFinder™ (GF) and an integrated functional nucleic acid (FNA). In the absence of Hg(2+) and Pb(2+), GF intercalated with the FNA and released moderate strong fluorescence. While in the presence of Hg(2+) or Pb(2+), the FNA would be induced to form T-Hg(2+)-T or G-quadruplex structure, interacted with which the GF would exhibit extremely strong or very weak fluorescence. By monitoring the fluorescence changes upon addition of these two ions, the Hg(2+) and Pb(2+) could be selectively detected as low as 3.23 ppb and 2.62 ppb. As the main advantage of this assay is simplicity and the feasibility was demonstrated by detecting Hg(2+) and Pb(2+) in spiked water samples, this assay holds great potential for the development of a cost effective and useful tool for environmental monitoring.