A competitive immunochromatographic assay based on a novel probe for the detection of mercury (II) ions in water samples

Mercury ions (Hg2+) are one of the most dangerous pollutants. Even at low concentration, it causes serious environmental and health problems. Current methods for the detection of Hg2+ in environmental samples are tedious and time consuming because they require sophisticated instrumentation and complicated sample pre-treatment processes. In this work, a novel probe with high selectivity towards Hg2+ was synthesized and a one step competitive immunochromatographic assay based on the probe for the detection of Hg2+ was developed and applied for water samples. The detection conjugate was immobilized on one end of the nitrocellulose membrane (detection line) and anti-BSA polyclonal antibody was immobilized on the other end of the membrane (control line). Hg2+ in samples competed with the probe to bind with immobilized detection conjugate. The visual detection limit of Hg2+ in spiked water samples was found to be about 1 ppb. The qualitative assay can be performed within 15 min. The advantages of the technique are rapidity, low cost and without the need of any equipment and complicated sample preparation.