Reaction-Triggered ESIPT Active Water-Soluble Polymeric Probe for Potential Detection of Hg2+/CH3Hg+ in Both Environmental and Biological Systems

Mercury (Hg2+)-triggered desulfurization of 1,3-dithiolane to the formyl group formation process has been utilized here to develop a norbornene-based reaction-triggered ESIPT active probe (NT). Mercury (Hg2+) activated the excited-state proton transfer (ESIPT) process of both NT and its water-soluble polymer Poly-PEG-NT to change the emission from colorless to cyan-green. Due to the Hg2+-sensitive reaction site, NT and Poly-PEG-NT serve as highly selective and ultrafast detection systems with a limit of detection (LOD) of 8.2 nM and 107 nM, respectively. Additionally, NT can detect the organic mercury species (CH3Hg+) with a quick response time and an impressive LOD of 1.1 μM. Due to the water-soluble nature of Poly-PEG-NT, it has the capability of detecting Hg2+ in pure aqueous meda. Both these probes are capable of detecting Hg2+ in both environmental and biological systems with excellent efficiency. Overall, the easy synthesis, cost-effectiveness, ultrafast detection, high selectivity, and sensitivity of NT and Poly-PEG-NT toward Hg2+/CH3Hg+ can be used for practical purposes with efficiency to counter mercury toxicity.