Novel biosynthesis of silver nanoparticles using Ulva lactuca and their potential toward environment and agricultural purposes

Introduction In the global field of nanotechnology, the production of silver nanoparticles (AgNPs) is an environmentally beneficial technique. To prevent the diseases caused by many commonly used pesticides, it is essential to synthesize safe alternatives from low-cost sources. Material and methods This study focuses on the eco-friendly extracellular production of AgNPs using an aqueous extract of Ulva lactuca as a reducing agent in a silver nitrate solution. The biosynthetic reaction was confirmed through various analytical techniques, including ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and energy dispersive X-ray analysis (EDAX). Moreover, antioxidant activity was confirmed. It has also been evaluated against a variety of bacteria and fungi that have an impact on humans, animals, and plants. Results and discussion The mean size of the nanoparticles (NPs) varied from 45–61 nm. The disk diffusion testing results show that, in comparison to the tested antibiotics, Staphylococcus aureus , Escherichia coli , Staphylococcus epidermidis , and Klebsiella pneumoniae were more responsive to U. lactuca -silver nanoparticles (U-AgNPs) extract. eldor 50% sc fungicide was used at the prescribed dose of 0.5 μL/mL, and the antifungal activity of aqueous and U-AgNPs extracts was examined at three concentrations of 0.62, 1.25, and 2.5 mg/mL. Through the suppression of spore germination, in vitro investigations demonstrated that U-AgNPs at varying doses greatly hindered the process of reproductive growth of Botrytis cinerea . Comparing U-AgNPs to the standard synthetic fungicide Teldor 50% sc, it is noteworthy to observe that a substantial control efficacy against tomato and strawberry gray mold was noticed, especially at concentrations of 2.5mg/mL on the entire tomato and strawberry plants and also on the detached leaves and fruits without causing any appearance damage. In summary, this study advances the field of agronanotechnology by demonstrating the potential application of a fungicide based on NPs to prevent gray mold on tomato and strawberry plants in greenhouse environments and throughout the postharvest phase.