Experimental and theoretical investigations on wavelength-specific probe for divalent metal ion detection

Heavy metal ions are a major source of pollution in the environment since they are nondegradable and accumulate in human bodies, creating serious threats to human health and the ecosystem. Conventional heavy metal ion detection techniques are not generally suitable for onsite or rapid detection, as they frequently require highly sophisticated and costly equipment, expert operation, laborious sample preparation, restricted testing conditions, and professional operators. As a result, they are not well suited for real-time and quick detection in the field. Advances in chemical sensing and electronic communication have resulted in the invention of wireless chemical sensors. Smartphones are widely used along with sensors, including test strips, sensor chips, and portable detectors, for biochemical detection owing to their versatility and affordability. The development of chemical sensor technologies will lead to the fabrication of more compact, lightweight, affordable, adaptable, and long-lasting devices. Considering these shortcomings, we propose that chemical sensor systems that are coupled with wireless technology and smartphones represent an important component of the sensor Internet of Things. In this context, the easy-to-synthesize ligand 2-(2-(pyridin-2-yl)hydrazono)-1 H-indene-1,3(2 H)-dione (PHID) has been explored for sensing divalent Hg²⁺ and Cu²⁺.