Calotropis Gigantea Latex-Derived Zinc Oxide Nanoparticles: Biosynthesis, Characterization, and Biofunctional Applications

Latex of C. gigantea was used to synthesize zinc oxide nanoparticles (ZnO NPs) by the green chemistry approach. The crystalline size, shape, and purity of as-synthesized ZnO NPs were characterized through scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction analysis, and Fourier-transform infrared spectroscopy techniques. Crystalline, spherical ZnO NPs with an average size of 21.8 nm were formed. In addition, the biological properties of the ZnO NPs, such as antioxidant and antibacterial activity, were evaluated by 2,2-diphenyl-1-picrylhydrazyl assay and the agar well-diffusion method. The highest free radical scavenging activities of 83.11 ± 1.89 % were observed at a concentration of 350 μg/mL of C. gigantea latex-mediated ZnO NPs. The latex in the C. gigantea latex-mediated ZnO NPs inhibited the growth of pathogenic bacteria. The maximum zone of inhibition was found in P. aeruginosa and S. aureus. C. gigantea latex-mediated ZnO NPs have significant biocompatibility and broad-spectrum antibacterial properties against wound-causing bacteria and, therefore, can be suggested for use in the formulation of novel creams or gels for healing applications.