Green synthesis and characterization of nano zinc oxide and comparative study of its impact on germination and metabolic activities of Solanum lycopersicum L. and Capsicum annuum L.

The current work emphasizes green synthesis of nano-crystals of zinc oxide by treating zinc acetate dihydrate with aqueous leaf extract of Ocimum sanctum L. and study its effect on growth and metabolism of Solanum lycopersicum L. and Capsicum annuum L. vegetable crop plants. The presence of secondary metabolites in leaf extract, acting as a reducing agent for synthesized nanoparticles (NPs) was revealed by FT-IR spectral analysis. XRD-analysis was done to confirm the crystal nature of NPs. DLS particle size analyser was used to determine the size of zinc nano crystal and morphology was determined using SEM and TEM. Solanum lycopersicum L. and Capsicum annuum L. seedlings were treated with zinc oxide nanoparticles (ZnO NPs) at concentrations of 0, 10, 25, 50, 75, 100, 250, and 500 mg/L in a sand culture medium. The biophysical and biochemical parameters estimation was done by reporting the effects of nano-treatments on both seedlings. Exposure of nano-treatments in a dose-dependent manner on both seedlings shows the remarkable increase in plant enzyme protection. In an attempt to determine the safe and effective concentration of ZnO NPs with the least impact, it was found that the morphological and physiological characteristics of the seedlings were improved with lower doses as compared to higher doses. ZnO NPs significantly improved seed germination and seedling growth of Solanum lycopersicum L. and Capsicum annuum L. by improving the metabolism of plants.