Aptamer-based fluorescence-quenching lateral flow strip for rapid detection of mercury (II) ion in water samples.

Divalent mercury ion (Hg) is one of the most common and stable forms of mercury pollution. In this study, a skillfully designed lateral flow strip (LFS) was developed for sensitive detection of Hg in river water samples. Aptamer, a specific oligonucleotide probe, was used to selectively identify and target Hg instead of antibody in traditional immunechromatographic strips; and the fluorescence-quenching system was used to generate positive and low background florescence signals in the competitive-likely LFS. The linear detection range of the LFS for Hg was 0.13 ng mL to 4 ng mL and the limit of detection (LOD) was 0.13 ng mL. This test provided results in 15 min and demonstrated high specificity. For detection of Hg in river water, the results were consistent with inductively coupled plasma-mass spectrometry measurements. The aptamer-based fluorescence-quenching LFS was shown to provide a reliable, accurate method for rapid detection of mercury contamination. Graphical Abstract The principle of the aptamer-based fluorescence-quenching LFS.