Green Synthesis of Nanoparticles Using Plant Extracts: Applications in Environmental Remediation and Drug Delivery

The green synthesis approaches that minimize environmental and biological risks linked with traditional nanoparticle production are the ones driving the growing demand for sustainable nanomaterials. In this work, the natural plant Moringa oleifera was the leaf extract of which was the reducing and stabilizing agent for the synthesis of zinc oxide NPs. The total process was an eco-friendly and cheap one and it could be repeated without any difficulty. The visual and UV-Visible spectroscopy studies showed a characteristic absorption edge around 365 nm, which confirmed the existence of ZnO nanoparticles. The surface and structural characterization through FTIR, XRD, SEM/TEM, DLS, and zeta potential analysis demonstrated the production of crystalline, quasi-spherical nanoparticles with nanometric size and moderate colloidal stability. The functional properties of the produced ZnO nanoparticles were tested in two areas: environmental purification and drug delivery. The studies on photodegradation by using methylene blue as a model dye showed excellent degradation of about 83% in 120 minutes under light radiation. The process of degradation followed a pseudo-first-order model which proved the activity of the photocatalyst was effective. In the case of drug delivery evaluation, curcumin was loaded onto the ZnO nanoparticles with great loading efficiency. The in vitro release studies exhibited pH-responsive property where drug release was greater at acidic pH than at physiological pH thus indicating the potential of the system in the field of controlled drug delivery applications. Overall, the results demonstrate that Moringa oleifera–mediated ZnO nanoparticles possess favorable physicochemical properties and multifunctional potential for sustainable wastewater treatment and targeted drug delivery. This study supports the use of plant-based green synthesis strategies in developing eco-friendly and versatile nanomaterials for environmental and biomedical applications.