Green Synthesis Method of ZnO Nanoparticles using Extracts of Zingiber officinale and Garlic Bulb (Allium sativum) and Their Synergetic Effect for Antibacterial Activities

In this paper, antibacterial activities of zinc oxide (ZnO) nanoparticles synthesized through green method using garlic bulb (Allium sativum), ginger (Zingiber officinale) extracts, and their mixture are reported. The synthesized ZnO NPs were characterized by X-ray diffraction (XRD), ultraviolet visible (UV–vis), photoluminescence (PL), spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The crystalline sizes of ZnO NPs synthesized using garlic bulb (Allium sativum) extract, ginger (Zingiber officinale) root extract, and their mixture were 19.8, 21.94, and 23.86 nm, respectively. Similarly, the corresponding peak absorbances were 369.5, 377.5, and 374 nm, respectively. The antibacterial activities of synthesized ZnO NPs were tested against gram-negative bacteria Escherichia coli (E. coli) and Pseudomonas putida (P. putida) and gram-positive bacteria Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes). The ZnO NPs synthesized using the mixture of garlic bulb (Allium sativum) and ginger (Z. officinale) root extract have shown maximum inhibition zone against gram-negative bacteria (P. putida: 28.67 ± 0.82 mm) and gram-positive bacteria (S. pyogenes: 10.67 ± 0.47 mm) as compared to ZnO NPs synthesized using the two extracts separately. On the other hand, ZnO NPs obtained from garlic bulb and Z. officinale root extracts exhibited maximum inhibition zone against E. coli (19 ± 0.82 mm) and S. aureus (16.4 ± 0.47 mm), respectively.