Binding properties and biological applications of green synthesized ZnO nanoparticles from neem flower

Zinc oxide (ZnO) nanoparticles exhibit distinctive electronics, sensors, and biomedical applications. The present work aims to synthesize an eco-friendly, cost-effective, and sustainable approach for the fabrication of zinc oxide nanoparticles (ZnO NPs). An aqueous extract of neem flowers was used to fabricate the ZnO NPs as a natural reducing and capping agent. Analytical techniques, including UV-Vis, TEM, FTIR, FESEM, XRD, zeta potential analysis, and TGA confirmed the successful formation, crystalline nature, and stability of the ZnO NPs. The synthesized ZnO NPs were confirmed by the peak at 363 nm in the UV-Vis spectrum. The average particle size was found between 30 ~ 60 nm by FESEM, TEM, and Particle Size Analysis. The ZnO NP shows the highest % of inhibition was found to be > 80% in antioxidant activity. The antimicrobial assays show promising activity against pathogens. Moreover, their interaction with biomolecules such as DNA and bovine serum albumin (BSA) demonstrated strong binding affinity, highlighting their potential for biomedical applications. Cytotoxicity analysis using HEK-293 cells revealed minimal toxicity, suggesting that these nanoparticles are safe for normal cells. This study highlights the potential of green-synthesized ZnO nanoparticles as a promising option for therapeutic, antimicrobial, and bioengineering applications.