Selective and sensitive colorimetric detection of mercury ions in aqueous solutions using silver nanoparticles synthesized in innovative biomaterial matrix

The detection of toxic metal ions from water is one of the paramount requirements to combat a typical water pollution problem. Herein, we report a simple and rapid solution for the precise detection of mercury which is one of the toxic metals causing the majority of water pollution diseases. We have explored the chemobiologically synthesized silver nanoparticles in mucus matrix of Achatina fulica snails. The silver nanoparticles play a key role in the sensing of heavy metals. The resultant nanobiocomposite samples were subjected to characterization by UV-Vis spectroscopy, FESEM, and XRD. In a preliminary attempt to develop hassle-free on-site screening protocol, such green hybrid systems were endeavored for selective colorimetric detection of mercury in a solution. Colorimetric detection enables cost-effective and simple monitoring of toxic ions accompanied with the advantage of on-site applicability with avoidance of complex instrumentation and ease of analysis with practical usage. Peculiarly, our simple bio-interfacial sensing approach reveals highly selective colorimetric sensor response down to ppb level for mercury ions analyte. Along with mercury, the other metal ions such as Co, As, Zn, Ni, Pb, Cu, and Fe were also tested for sensing to check the cross-sensitivity.