Evaluating The Antibacterial Activity Of Greener Synthesized Silver Nanoparticles As An Example Of Sustainable Nanoscience In Early Undergraduate Curriculum

Abstract

Silver nanoparticles (AgNPs) can damage and destroy bacteria upon contact with each other, illustrating their ability to exert antibacterial properties. Traditionally, AgNPs are synthesized using sodium borohydride to reduce silver nitrate to metallic silver and a polyvinylpyrrolidone (PVP) coating would be used to further stabilize the particles. To develop a more sustainable and economical AgNPs synthesis, lemon extract was substituted as the reducing and stabilizing agent. Furthermore, these AgNPs were characterized using the ultraviolet-visible (UV-vis) spectrophotometer over time, to evaluate the stability of the particles. Then, the AgNPs were tested against Gram-negative bacteria, Escherichia coli (E. coli), and Gram-positive bacteria, Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis) to which their inhibition rings were measured. In this thesis, our preliminary data have shown that the greener synthesis of AgNPs using lemon extract had been effective against both type of bacteria. Additionally, the greener synthetic method was developed using a hot water bath, over the usual use of either an ultrasonic or thermostatic bath. Because of that, this budget- and eco-friendly alternative method could potentially be used in a first-year chemistry laboratory class to introduce students to the multidisciplinary field of nanotechnology by merging green chemistry and biology.