Spectroscopic Studies and Numerical Modelling on Nanoparticle based Toxic Heavy Metal Sensor for the Development of a Low-Cost Prototype in Field Use

With the advent of technology, a sustainable solution of environmental pollution is the selective monitoring of pollutants in the environment. Herein, we report a spectroscopic detection of lead (Pb), one of the toxic heavy metal pollutants. Spectroscopic studies have been utilized to study the self-aggregation of citrate functionalized gold nanoparticles in presence of lead. The Longitudinal Surface Plasmon Resonance (LSPR) of gold nanoparticles increases as the lead concentration increases, and a new peak emerges in the red region of the EM spectrum indicative of the generation of larger aggregates. We have used quasi-static approximation based numerical modelling to determine the percentage of aggregation of the gold nanoparticles in presence of P$\mathrm{b}^{2+}$ ions. We are of the opinion that these key findings will pave the path towards the development of low-cost lead sensor for monitoring of lead pollution in the ecosystem. We have developed a prototype for the measurement of heavy metal toxicity in real world applications in a cost effective way.