ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF PHYTOSYNTHESISED ZnOs BY Hibiscus tiliaceus LEAF EXTRACT AGAINST FOUR PATHOGENIC BACTERIA

The numerous benefits provided by Zinc oxide have attracted attention. Therefore, plenty of ZnO synthesis methods have been developed. This study reported the phytosynthesis of ZnOs by Hibiscus tiliaceus leaf extract, the characterization of phytosynthesised ZnOs, and their antibacterial and antioxidant activities. The H. tiliaceus leaf extract was prepared with distilled water and distilled water/ethanol mixtures at three different ratios. The characteristics of the phytosynthesised ZnOs were revealed by infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. A spectrophotometric technique was enforced to investigate the antioxidant activity of phytosynthesised ZnOs and the total phenolic level of the extracts. The antibacterial activity was assayed against four pathogenic bacteria. The particle sizes of the phytosynthesised ZnOs were 46 nm to 273 nm with rod and hexagonal shapes. The highest DPPH free radical scavenging activity was shown by phytosynthesised ZnOs produced from extract with a ratio of aqua dest: ethanol, which was 1:1 (v/v). Strong antibacterial activity toward Staphylococcus epidermidis was displayed by phytosynthesised ZnOs compared to Staphylococcus aureus, Escherichia coli, and Salmonella typhi. The phenolic and flavonoid compounds of H. tiliaceus leaf extract affected the antioxidant activity of phytosynthesised ZnO. The inhibition zones of some phytosynthesised ZnOs were better than pharmaceutical-grade ZnO.