Biosynthesis, characterization, and antibacterial activity of ZnO nanoaggregates using aqueous extract from Anacardium occidentale leaf: comparative study of different precursors

Abstract Background Various parts of Anacardium occidentale plant possess curative qualities like antidiabetic, anti-inflammatory, antibacterial, antifungal, and antioxidant. Aqueous extract this leaf was used in biosynthesizing zinc oxide (ZnO) nanoaggregates using two precursors salt (zinc acetate dihydrate [Zn(CH 3 COO) 2 ?2H O] chloride [ZnCl ]). The synthesized ZnO samples were a comparative study to investigate the antibacterial activity against selected Gram-positive Gram-negative microbes [ Staphylococcus aureus , Exiguobacterium aquaticum (Gram +ve) Escherichia coli Klebsiella pneumoniae Acinetobacter baumannii ?ve)]. from characterized Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission (TEM), energy-dispersive x-ray (EDX) techniques. Results Micrographs SEM TEM confirmed nanoparticles agglomerated into aggregates. While spherical identified prepared Zn(CH O, flake-like structures ZnCl . Particle size determined by 107.03 ± 1.54 nm 206.58 1.86 for respectively. nanoaggregate as precursor gave higher than its counterpart, with K. pneumonia recording highest inhibition zone 2.08 0.03 mm (67.53%) whereas S. recorded least 1.06 0.14 (34.75%) precursor. Also, increases increasing concentration general. However, A. E. did not follow continuity trend regards 250 ppm 500 concentrations. Conclusion Biosynthesis aqueous successful formation nanospheres nanoflakes. suggested that sp. could be an alternative source production are efficient compounds both Gram +ve ?ve promising effect infectious bacteria.