Mycosynthesis of Silver Nanoparticles from Ganoderma Lucidum: Optimization, Antioxidant Activity, and Identification of Capping Agents

Silver nanoparticles (AgNPs) attracted great interest due to their advantages with respect to their physicochemical properties. Employing the green approach, this work explored the synthesis of AgNPs using Ganoderma lucidum, investigated the metabolites that act as capping agents, and studied their antioxidant properties. To obtain the synthesis optimal condition, Central Composite Design (CCD) was utilized. The optimal conditions identified were pH=10, Temp (°C)=65, Time (min)=120, Vol
extract
(mL)=3.5, and Vol
AgNO3
(mL)=20. Surface plasmon resonance (SPR) was observed using UV-vis spectroscopy at 420 nm. SEM and TEM analysis showed that G. lucidum-AgNPs are generally shaped spherically with 21.66±4.22 nm diameters. FT-IR established the existence of organic compounds (C-H, O-H, N-H, C-O, and C-N). EDS analysis confirmed the presence Ag, C, N, and O atoms. LC-MS/MS analysis tentatively identified capping molecules (Epicatechin-6- glucoside, ergothioneine, and (Z)-9- Octadecenamide, etc.). G. lucidum-AgNPs were relatively stable in solution with a zeta potential of -14.7 mV and its %Inhibition in anti-oxidation assay was higher than its aqueous extract and chemically synthesized AgNPs indicative of synergistic action in radical scavenging.