Comparative study of well diffusion and disc diffusion method to investigate the antibacterial properties of silver nanoparticles synthesized from Curcuma longa extracts

Abstract

Green synthesis method for the preparation of silver nanoparticles (AgNPs) using Curcuma longa extracts as reducing and stabilizing agents was studied. The optimization of the synthesis was determined by varying the weight of the extracts, the AgNO3 concentration, and the reaction time. The results revealed that 3 g of extracts, 0.005 M AgNO3, and 30 min of incubation time were the ideal conditions to synthesize AgNPs-Cur. The characterization was assessed by UV-Visible spectroscopy, FTIR, and TEM. UV-Vis spectra showed a surface plasmon resonance (SPR) peak at 428 nm with the stability after 5 months of storage time. FTIR analysis revealed the formation of AgNPs using turmeric extracts and the synthesized AgNPs-Cur had the average size of 22.12 ± 0.60 nm (analyzed by TEM). The well diffusion and disc diffusion method were performed to investigate the antibacterial activity of AgNPs-Cur against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results concluded that AgNPs-Cur exhibited better bacterial growth inhibitory activities with well diffusion method than disc diffusion method.