Green synthesis of silver nanoparticles using Aspergillus niger and its impact on seed germination, growth and biochemical aspects of Vigna radiata (L.)

Green synthesis of Silver nanoparticles (AgNPs) has emerged as a recent trend in nano biotechnology. However, their applications in agriculture remain largely unexplored. The research was carried out to investigate the effect of AgNPs on Vigna radiata (L.). The AgNPs were synthesized from silver nitrate aqueous solution through a simple, eco-friendly and cost effective way using Aspergillus niger. The synthesis of AgNPs was confirmed by scanning through UV-Vis spectrometry which revealed maximum absorption near 420 nm. The particles were further characterized by Nanoparticle tracking analysis which showed 49 nm size particle. Different concentrations of AgNPs (20, 40, and 60 ppm) were applied to Vigna radiata to evaluate their impact on seed germination, root and shoot length, and key biochemical markers, chlorophyll and protein content. The results demonstrated that lower concentrations (20 ppm) of AgNPs promoted seed germination and early seedling vigour compared to control, showing enhanced growth of seedlings. However, higher concentrations (60 ppm) negatively affected seed germination. The total chlorophyll content was significantly increased at 20 ppm (5.95 mg/ 100 g); however, further increases in the dose resulted in a decline in total chlorophyll content. The protein content was observed maximum at 20 ppm (2880 mg/100 g). However, the protein content was decreased with increasing concentrations, indicating a dose-dependent phytotoxic impact. The study reports the green synthesis of silver nanoparticles (AgNPs) using Aspergillus niger and their application on Vigna radiata (L.) AgNPs (~ 49 nm) were characterized by UV-Vis spectroscopy and nanoparticle tracking analysis. Different concentrations (20, 40, 60 ppm) were tested for their effects on seed germination, seedling growth, chlorophyll, and protein content. Results revealed that low concentrations (20 ppm) enhanced germination, seedling vigour, chlorophyll, and protein levels, while higher concentrations (60 ppm) showed phytotoxic effects, indicating a dose-dependent dual role of AgNPs in plant growth.