Turn-on Fluorescence Detection of Mercury(II) Ion using a Triazole thiol indole Derivative and Gold Nanoparticles

Development of simple, rapid and cost-effective methods for detection of mercury ions in environmental samples has a great importance due to the serious health risk of Hg2+ ions poses to human [1]. A new and sensitive fluorescent nanosensor was proposed for Hg2+ detection based on covalent bonding of S-H group [2, 3]. The design of the nanosensor was carried out using a new synthetic organic ligand which was a derivative of Triazole thiol indole. The ligand was assembled on the chemically prepared gold nanoparticles (Au NPs) to enhance the sensitivity and repeatability of the response [4]. The proposed nanosensor showed a fluorescence emission at 477 nm by exciting at 360 nm. Upon the addition of Hg2+, ions, the fluorescence intensity of the probe increased linearly in the range from 1×10-7 to 5×10-6 mol L-1 with detection limit of 4.8×10-8 mol L-1. The strategy offered excellent selectivity toward Hg2+ in comparison with other metal ions. Meanwhile, this sensor was applied to determine Hg2+ ions in some water samples with satisfactory recoveries (94.3-103.7%).