Pb²⁺ sensing by coumarin sulphonamide hybrids in aqueous medium

Abstract

Metals play an important role in various metabolic activities in the human body, but above desired concentrations, a role reversal occurs that causes deadly outcomes viz., cancer. Metals cannot be cracked down and are non‐biodegradable. It is the bioaccumulation of toxic metals inside the biomatrices, that further intensifies the research on different means of metal detoxification from different matrices. Among heavy toxic metals lead is a brutal carcinogen that requires pitiless sensors for its capturing. The use of heterocycles for metal sensing in supramolecular chemistry is preferred due to the strong chelation they offer to toxic metals. The C1–C3 probes were synthesized and studied for their Pb2+ binding ability. All the probes were prepared by treating bromoacetyl coumarin with camphor sulphonamide, 5‐dimethylamino‐1‐naphthalene sulphonamide, and methyl‐2‐amino‐sulphonyl benzoate at room temperature. The probes show selective binding with Pb2+ ions in aqueous acetonitrile among different tested metal ions viz., Cu2+, Zn2+, Ni2+, Mn2+, and Pb2+ ions as shown in ultraviolet (UV)‐visible, nuclear magnetic resonance (NMR), and high‐performance liquid chromatography (HPLC) studies. These sulphur‐containing probes bind very well with Pb2+ ions by offering selectivity in binding positions that capture lead ions at their minimum possible concentration.

Two near-infrared fluorescent probes based on dicyanoisfluorone for rapid monitoring of Zn2+ and Pb2+

“…So far, many probes for detecting Zn 2+ and Pb 2+ have been reported. Nevertheless, their fluorescent signals are mainly located at blue and green light regions [27][28][29][30][31][32][33][34][35][36][37][38]. Comparatively speaking, the near-infrared (NIR) fluorescent probes can effectively avoid the interference of sample background, and have better application potential.…”