Optimization of processing parameters in green synthesis of gold nanoparticles using microwave and edible mushroom (Agaricus bisporus) extract and evaluation of their antibacterial activity

Gold nanoparticles (AuNPs) were synthesized using edible mushroom Agaricus bisporus extract as both reducing and stabilizing agents via microwave irradiation method. The effects of the microwave exposure time and the amount of HAuCl4 solution (1 mm) on the mean particle size, concentration, and polydispersity index (PDI) of the synthesized AuNP solution were investigated using response surface methodology. Mushroom extract was characterized by Fourier transform infrared. The synthesized AuNPs were characterized by dynamic light scattering, UV- Vis spectroscopy, and transmission electron microscopy. Well-dispersed and spherical AuNPs with the minimum mean particle size and PDI, and maximum concentration and zeta potential of 33.56 +/- 1.8 nm, 0.855 +/- 0.02 ppm, 148.88 +/- 2.7 ppm, and + 17.2 mV, respectively, were obtained using 2.62 ml of HAuCl4 and 0.2 ml of mushroom extract for 55 s. The antibacterial activity of the fabricated AuNPs was assessed against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria and was found to be possessing high bactericidal effects.