Cost-effective synthesis of bifunctional silver nanoparticles for simultaneous colorimetric detection of Al(III) and disinfection

The functionalization of nanoparticles (NPs) by utilizing biologically important substances through a green route is a novel aspect of the design of a colorimetric sensor. In this work, we use the bifunctional Jamun (Syzygium cumini) stabilized silver nanoparticles (J-AgNPs) for simultaneous colorimetric detection of Al(III) and the disinfection of synthetic and real contaminated groundwater samples. The J-AgNPs were prepared under natural sunlight irradiation by utilizing Jamun leaves extract (JLE) as both the reducing agent and the stabilizer. The lower detection limit for Al(III) with this method is 0.01 ppm (S/N = 3), which falls within the permissible limits set by the Environmental Protection Agency (USEPA), that is, 50 ppm. The proposed method also displays the excellent antibacterial activity with the value of 45 μg/mL (IC50) for S. aureus bacteria and 25 μg/mL (IC50) for E. coli bacteria. The estimated total cost of the prepared nanosensor (100 mL) is US $ 0.03, which makes the present method cost-effective in areas with resource-limited settings. As far as we know, this is the first study to use natural sunlight as a source of energy for the generation of J-AgNPs in an aqueous medium, making the process environmentally friendly, attractive and efficient.