Synthesis of silver nanoparticles using <i>Fagonia cretica</i> and their antimicrobial activities

Abstract

Silver nanoparticles (NPs) were synthesized using an efficient bioreducing agent from <i>Fagonia cretica</i> extract having the advantage of eco-friendliness over chemical and physical methods. The sharp color change and appearance of representative absorption peaks in the UV-visible spectra confirm the quick reduction of the Ag salt and evolution of Ag NPs. Morphological and structural aspects showed that the resulting Ag NPs are highly crystalline with an average size of 16 nm. Furthermore, compositional analysis of the extract confirmed the existence of active bioreducing and stabilizing agents in the <i>Fagonia cretica</i> extract. Furthermore, various concentrations of AgNO₃ and the <i>Fagonia cretica</i> extract were employed to obtain a higher yield with better stability of Ag NPs. The resulting Ag NPs showed effective antibacterial activity against <i>Proteus vulgaris</i>, <i>Escherichia coli</i>, and <i>Klebsiella pneumoniae</i>. It is found that the Ag NPs induce maximum production of reactive oxygen species (ROS) in <i>Proteus vulgaris</i> as compared to <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i> which induce cell toxicity, while ROS production in the presence of Ag NPs is 30% higher than that in the presence of only the plant extract and control in all three bacterial strains. Thus, present findings show that plant extracts can be a useful natural resource to prepare functional nanomaterials for targeted applications especially in the field of biotechnology.