Synthesis of eco-friendly facile nano-sized zinc oxide particles using aqueous extract of Cymodocea serrulata and its potential biological applications

Green synthesis of nanoparticles is an emerging branch of nanotechnology due to its low cost and effectiveness. In this study, zinc oxide (ZnO-NPs) nanoparticles were biosynthesized by an eco-friendly method using Cymodocea serrulata . They were characterized by Ultraviolet–visible (UV–vis) spectroscopy, energy-dispersive X - ray (EDX), scanning electron microscopy (SEM), X-ray diffractometer (XRD), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. The synthesized crystalline nanoparticles were found to be 26.0–52.0 nm in size. The antioxidant activity of synthesized ZnO nanoparticles at 1000 µg/ml have revealed 75.55% in DPPH, 69.5% in deoxy-ribose, 62.75% in ABTS, 71.25% in nitric oxide and 74.10% in superoxide-scavenging assays. They also depicted significant bactericidal action against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae , and Shigella flexneri . ZnO nanoparticles at 100 µg/ml concentration showed increased inhibition against B. subtilis with 18.0 mm, whereas moderate inhibition was seen against S. flexneri with 14.3 ± 0.25 mm. The cytotoxicity of ZnO-NPs was evaluated on A549 and H520 cell lines. The anti-proliferative effect was seen at 120 µg concentration on A549 and H520 cell lines with IC 50 values of 55.0 ± 0.25 and 60.0 ± 0.50 µg/ml at 24 h. C. serrulata -coated zinc nanoparticles was found potential against bacterial pathogens and cancer cells. Therefore, they may be developed in future for biomedical applications.