Pomegranate Peel Extract-Mediated Green Synthesis of ZnO-NPs: Extract Concentration-Dependent Structure, Optical, and Antibacterial Activity

Abstract

Plant-based nanoparticles (NPs) have many advantages over physical and chemical methods and featured with several medicinal and biological applications. In this study, zinc oxide NPs (ZnO-NPs) were synthesized using pomegranate peel aqueous extract, under mild and ecofriendly conditions. The ZnO-NPs structure, morphology, and optical properties were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared (FTIR), and ultraviolet-visible (UV-Vis). Antibacterial activity against Gram-positive and Gram-negative strains were evaluated using the disk diffusion method. The effect of extract concentration (20, 30, and 40 mL) on the final properties of NPs, as well as the NPs concentration used for antibacterial test (50, 100, and 200 mg/mL), were also studied. The results indicate a hexagonal structure with particle size increases as extract concentration increase (D = 18.53, 29.88, and 30.34 nm), while the optical bandgap was decreased (Eg = 2.87, 2.80, and 1.92 eV). The antibacterial activity of ZnO-NPs indicated high efficiency, similar or even higher than that of the control azithromycin, more against S. aureus, increased with NPs concentration, and preferred when NPs prepared from high extract concentration. Such promising physicochemical properties support the usefulness and efficacy of the reported bio-route for production of ZnO-NPs and may encourage its application for large-scale production.

Garlic Extract-Mediated Synthesis of ZnS Nanoparticles: Structural, Optical, Antibacterial, and Hemolysis Studies

“…These results are comparable to some other synthesized ZnS NPs [2,9,42,43]. For example, the D value calculated by XRD method for ZnS NPs obtained by, e.g., sol-gel (29.0 nm) [9], Praepagen HY (an alkyl ammonium salt; 4.8 nm) [42], solid-state (4.6), glucose-mediated (5.3) [24], starch-capped (3.3 nm) [43], polyvinyl alcohol-capped (2.9 nm) [43], and uncapped (3.7 nm) [2] were close to obtained one of 2.3 nm.…”

“…Additionally, the lattice parameters a, b, and c (5.357 Å), the unit cell volume (153.732 Å 3 ), space group (F43m), and density (3.9 g/cm 3 ) of synthesized sample were calculated following formula described elsewhere [40,41]. These results are comparable to some other synthesized ZnS NPs [2,9,42,43]. For example, the D value calculated by XRD method for ZnS NPs obtained by, e.g., sol-gel (29.0 nm) [9], Praepagen HY (an alkyl ammonium salt; 4.8 nm) [42], solid-state (4.6), glucose-mediated (5.3) [24], starch-capped (3.3 nm) [43], polyvinyl alcohol-capped (2.9 nm) [43], and uncapped (3.7 nm) [2] were close to obtained one of 2.3 nm.…”

“…NPs. The biosynthesis of ZnS NPs was carried out as described in literature [2,7], with slight modification. Thus, stochiometric (0.02 mol) solutions of zinc nitrate (6 g in 25 mL) and sodium sulfide (2.6 g in 25 mL) were separately prepared by dissolving the corresponding salt in dH 2 O with magnetic stirring for 15 min.…”

“…Hemolytic activity of the synthesized ZnS NPs was evaluated against human erythrocytes over a concentration range of 3.12-100 μg/mL. The assay was carried out as previously described [2,34] with few modifications. Briefly, 5 mL of blood was taken from a healthy male volunteer (25 years old, B-positive blood group) after the provision of informed consent.…”

“…Although various chemical methods can be applied for the synthesis of NPs, bio-approach is considered safer, ecofriendly, and low cost. Therefore, plant-mediated synthesis of NPs has become an innovative industrial technique with plenty of benefits due to plant obtainability and uncostly, the method simplicity and scaling up possibility, and the NPs obtained size and shape tailorability [2,3].…”