Selective Colorimetric Sensor for the Detection of Hg~(2+) and H2S in Aqueous Medium and Waste Water Samples

摘要

Dabsyl based new colorimetric sensor 1 for the selective detection of environmentally most important cation Hg2+ and biologically important hydrogen sulfide (H2S) in aqueous medium have been reported. The probe 1 selectively responded to Hg~(2+) among various cations and shows colour change from yellow to red with the bathochromic shift in Uv-Vis spectrum via intramolecular charge transfer (ICT) mechanism. The limit of detection for mercury was determined as 80 mM. The possibility of using 1 to detect mercury in industrial waste water samples was also explored with good recovery value. The ensemble 1.Hg~(2+), also applicable for the detection of H2S (LOD = 28 mM) in water among different bio-thiols and anions. H2S displaces the mercury from 1.Hg~(2+) via metal displacement approach and regenerates the original probe 1 within few seconds. Regenerated receptor 1, further used for the detection of mercury ion. Receptor 1 incorporated test paper and polymer based thin films were used as a portable kit for the selective colorimetric detection of mercury and H2S in water.