Green fabrication of Ag–Ni–Mn-Zn nanoparticles from watermelon peels and its antioxidant, dye degradation and molecular docking studies

Nanotechnology is revolutionizing various sectors, including materials science, electronics, medicine, and energy. This study investigates the use of biowaste i.e. watermelon peels for the sustainable synthesis of Ag–Ni–Mn–Zn quadmetallic nanoparticles. These nanoparticles showed promise for antioxidant, catalytic, and anti-cancer applications. Watermelon peel extract acts as a reducing and stabilizing agent. Techniques like Ultraviolet–Visible Spectroscopy (UV–Vis Spectroscopy), Zeta potential, Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray Spectroscopy (EDX), and X-ray Diffraction (XRD) were used to characterize the nanoparticles. Molecular docking analysis was done to assess their interactions with Extracellular signal-regulated kinase 2 (ERK2) and catechol complexes. The green fabrication approach is environmentally sustainable, using waste materials and reducing reliance on chemical synthesis methods. The synthesized nanoparticles showed potential antioxidant activity and can degrade dyes such as methyl red, phenol red, and eosin yellow effectively. The average crystal size of the nanoparticles was 386.408 nm. The hydrodynamic diameter of the nanoparticles was 1187.9 nm. The average zeta potential was −14.8 mV, indicating high stability. At a concentration of 1000 µg/ml, the nanoparticles showed scavenging activity of 90.04%. In degradation tests, methyl red showed the highest degradation rate at 97.67% within 60 min followed by phenol red and eosin yellow Complex dye mixture showed 73.48% degradation efficiency. The synthesized compounds could serve as lead compounds for further optimization and exhibit anti-cancer properties, as shown by molecular docking data. Further research is suggested to optimize these particles and additional applications can be done. There investigations could explore their potential in agricultural applications, including crop protection, nutrient delivery, and soil remediation. Such endeavours would not only advance the field of nanotechnology, but also contribute to sustainable agriculture practices, promoting environmental health and food security.