green synthesis of gold nanoparticles using barberry and saffron extracts

recently, synthesis of gold nanoparticles (aunps) is the subject of a lot of studies due to various applications in medicine, agriculture, and industry. the development of non-toxic and safe methods such as green chemistry to produce aunps is obviously recommended. in the current study, 2 antioxidant rich herbs of barberry and saffron stigma were applied as reducing agents for the 1-pot synthesis of size-controlled aunps. these aunps were characterized through ultraviolet-visible spectrophotometry (uv-vis), transmission electron microscopy (tem), and x-ray diffraction (xrd) techniques. optimal temperature and ph for the biosynthesis of aunps conjugated with herbs were 50°c and 7.5, respectively. xrd and tem results authorized aunps production in 5 - 15 nm for barberry and 5 - 10 nm for saffron and confirmed the stability, sphericity, and uniformity for both the nanoparticles.