Green synthesis of gold nanoparticles using Kaempferia parviflora rhizome extract and their characterization and application as an antimicrobial, antioxidant and catalytic degradation agent

Abstract Background Plant based synthesis of nanoparticles is a green chemistry approach which links plants with nanotechnology and look to be the best substitute against synthetic nano-products. Gold nanoparticles (AuNPs) mediated plant extracts are providing huge biological and environmental applications including antioxidant, anti-inflammatory, antimicrobial anticancer activities and catalytic action. Kaempferia parviflora (K. parviflora) is a medicinal plant commonly known as black ginger (BG), which has extensive pharmacological activities. Ecofriendly AuNPs was synthesized using an aqueous extract of K. parviflora rhizome. The synthesized black ginger gold nanoparticles (BG-AuNPs) was stabilized by chloroauric acid (0.1 mM) and the reaction was completed by 30 min at 30°C. The BG-AuNPs were characterized by UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Significant findings The TEM analysis confirmed the BG-AuNPs were well dispersed and smooth surfaced spherical structure with high crystal in nature. The BG-AuNPs showed an excellent antimicrobial activity against both Gram negative and Gram positive microbes and also provided the high antioxidant ability. The BG-AuNPs is a potent catalyst in the MO degradation using sodium borohydride.