Phytofabricated silver and silver–copper nanoparticles as nanopriming agents for improved germination and seedling development in <i>Vigna radiata</i>

The traditional approaches used in the formation of nanoparticles rely heavily on the use of destructive chemicals and require a high level of energy, thus reducing their viability in sustainable agriculture. Hence, the need for the preparation of environmental-friendly nanopriming agents for seed germination and primary growth of plants is increasing day by day. This work sought to prepare the silver nanoparticles (AgNPs) and the silver-copper bimetallic nanoparticles (Ag/CuNPs) via the Tephrosia purpurea leaf extract and examine their impact on the germination and development of the Vigna radiata seeds. The prepared nanoparticles were analyzed via UV-visible spectroscopy, XRD, FTIR, SEM/EDX, DLS, and fluorescence analysis. Different concentrations of the nanoparticles were used to investigate their influence on seed germination, seedling vigor, growth parameters, pigmentation, and phytochemicals. The characterization analysis revealed the successful fabrication of the nanoparticles. Both nanoparticles were found to enhance seed germination and growth, with the Ag/CuNPs exhibiting better results. The best germination percentage (100%) and growth parameter values were recorded in the case of 30 mg/L Ag/CuNPs. The study illustrates that bio-prepared Ag/ Cu bimetallic nanoparticles have great potential to act as nanopriming agents in promoting seed germination and early development of V. radiata.