Green synthesis of silver nanoparticles by Phoma glomerata

• Rapid mycofabrication (within 5 min) of SNPs was observed in the presence of bright sunlight.
• The mycofabrication of NPs by Phoma glomerata is also affected by the parameters like temperature, pH, silver nitrate concentration and fungal filtrate concentration. In the study temperature 25 °C and alkaline pH was found optimum for superior synthesis.
• The effect of substrate concentration (silver nitrate) and enzyme concentration (fungal filtrate) concludes that the mycofabrication is not an enzyme catalyzed process, since it fails to follow Michaelis–Menten kinetics for enzyme catalyzed reaction.
• Three-step mechanism for the mycofabrication of spherical NPs by P. glomerata was proposed: (1) activation, (2) nucleation and (3) reduction.
• The mycofabrication of SNPs by P. glomerata is rapid, easy and eco-friendly method.

We report an extracellular synthesis of silver nanoparticles (SNPs) by Phoma glomerata (MTCC-2210). The fungal filtrate showed rapid synthesis in bright sunlight. The Fourier transform infrared spectroscopy (FTIR) revealed the presence of a protein cap on the silver nanoparticle, which leads to increase stability of SNP in the silver colloid. X-ray diffraction (XRD) analysis showed the number of Bragg's reflection, which are due to the face centered cubic structure of the crystalline SNPs. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), nanoparticle tracking and analysis (NTA) demonstrated the synthesis of polydispersive and spherical SNPs. Energy dispersive X-ray spectroscopy (EDX) was used to confirm the elemental composition of the sample and Zeta potential measurement was carried out to determine the stability of mycofabricated SNPs.The alkaline pH, room temperature, sunlight demonstrated optimum synthesis. Apart from the physical conditions, concentration of silver nitrate and amount of fungal filtrate affects the mycofabrication process. The study of cultural and physical parameters during the mycofabrication of SNPs by P. glomerata will be helpful in order to increase the yield of mycofabricated SNPs of desired shape and size. The process of mycofabrication of SNPs by P. glomerata was found to be eco-friendly, safe and cost-effective nature.