The Role Of Cucurbitaceae Family "Pumpkin" Seed Aqueous Extract In The Synthesis Of Zinc Oxide Nanoparticles And Their Potential Applications As Antimicrobial Agents

Zinc oxide nanoparticles (ZnO-NPs) have wide applications in various fields. Synthesis of nanoparticles using plants is an alternative to conventional physical and chemical methods. Due to its ease, eco-friendliness, broad antimicrobial activity and diverse applications in many health, agricultural fields etc., in this study, we present the synthesis of zinc oxide nanoparticles (ZnO-NPs) using pumpkin seed aqueous extract. The prepared ZnO-NPs were characterized using UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. In addition, this study determined the antimicrobial activity of zinc oxide nanoparticles synthesized using a reference strain of Candida albicans ATCC 10231 and four bacterial strains, including two Gram-negative strains, Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922, and two Gram-positive strains, Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 25973. These nanoparticles showed effective against most strains, with negligible activity against E. coli and no activity against Candida albicans. They are variable in their activity against the rest of the strains studied, e.g. Pseudomonas aeruginosa (15 mm at 80 μg/ml compared to 33 mm in CIP), Staphylococcus aureus (14.6 mm at 80 μg/ml compared to 33 mm in CIP), and no activity against most strains when using the 10 μg/ml concentration of ZnO nanoparticles.