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

Abstract 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.