Synthesis of zinc oxide nanoparticles (ZnO NPs) using pure bioflavonoid rutin and their biomedical applications: antibacterial, antioxidant and cytotoxic activities

The present study reports an eco-friendly green synthesis of zinc oxide nanoparticles (ZnO NPs) using the bioflavonoid rutin. The synthesized ZnO NPs were characterized by UV-visible spectroscopy, XRD, FE-SEM, EDX, FTIR and zeta potential analyses. FE-SEM image showed that the synthesized ZnO NPs were rod shaped. FTIR spectral studies confirmed the role of bioflavonoid rutin for the reduction, capping and synthesis of ZnO NPs. The green synthesized ZnO NPs showed significant antibacterial activity against both Gram-positive (B. subtilis and S. aureus) and Gram-negative (K. pneumoniae and E. coli) bacterial pathogens. However, the synthesized ZnO NPs were more effective against Gram-negative bacteria compared to Gram-positive bacteria. The in vitro antioxidant ability of ZnO NPs was investigated spectrophotometrically using DPPH and H2O2 assay. The percentage of antioxidant activity increased with increasing concentration of ZnO NPs. Furthermore, synthesized ZnO NPs showed effectiveness in inhibiting the human MCF-7 breast cancer cells. In conclusion, the synthesized ZnO NPs using bioflavonoid rutin might be used as a strong biocidal and antioxidant agent in biomedical and pharmaceutical industries.