Synthesis, Characterization, and Biological Properties of Iron Oxide Nanoparticles Synthesized from Apis mellifera Honey.

Green approaches for nanoparticle synthesis have emerged as biocompatible, economical, and environment-friendly alternatives to counteract the menace of microbial drug resistance. Recently, the utilization of honey as a green source to synthesize Fe2O3-NPs has been introduced, but its antibacterial activity against one of the opportunistic MDR pathogens, Klebsiella pneumoniae, has not been explored. Therefore, this study employed Apis mellifera honey as a reducing and capping agent for the synthesis of iron oxide nanoparticles (Fe2O3-NPs). Subsequent to the characterization of nanoparticles, their antibacterial, antioxidant, and anti-inflammatory properties were appraised. In UV-Vis spectroscopic analysis, the absorption band ascribed to the SPR peak was observed at 350 nm. XRD analysis confirmed the crystalline nature of Fe2O3-NPs, and the crystal size was deduced to be 36.2 nm. Elemental analysis by EDX validated the presence of iron coupled with oxygen in the nanoparticle composition. In ICP-MS, the highest concentration was of iron (87.15 ppm), followed by sodium (1.49 ppm) and other trace elements (<1 ppm). VSM analysis revealed weak magnetic properties of Fe2O3-NPs. Morphological properties of Fe2O3-NPs revealed by SEM demonstrated that their average size range was 100-150 nm with a non-uniform spherical shape. The antibacterial activity of Fe2O3-NPs was ascertained against 30 clinical isolates of Klebsiella pneumoniae, with the largest inhibition zone recorded being 10 mm. The MIC value for Fe2O3-NPs was 30 µg/mL. However, when mingled with three selected antibiotics, Fe2O3-NPs did not affect any antibacterial activity. Momentous antioxidant (IC50 = 22 µg/mL) and anti-inflammatory (IC50 = 70 µg/mL) activities of Fe2O3-NPs were discerned in comparison with the standard at various concentrations. Consequently, honey-mediated Fe2O3-NP synthesis may serve as a substitute for orthodox antimicrobial drugs and may be explored for prospective biomedical applications.

Green synthesis, characterization and applications of Phyllanthus emblica fruit extract mediated chromium oxide nanoparticles.

The green synthesis of metallic nanoparticles is attributable towards diverse applications in various fields, recently. In this research, we report simple and eco-friendly synthesis of chromium oxide (Cr2O3) nanoparticles using the fruit extract of Phyllanthus emblica as a reducing and capping agent. The absorbance peaks at 350 nm and 450 nm validated the nanoparticle formation in UV-visible spectrum. FTIR spectrum revealed the nature of functional groups. The crystalline properties of nanoparticles were ascertained by XRD analysis. EDX spectrum corroborated the elemental composition of nanoparticles in which chromium and oxygen constituted 68% of total weight. SEM images demonstrated agglomeration of nanoparticles resulting in the formation of large irregularly shaped flakes. Cr2O3 nanoparticles demonstrated excellent antimicrobial properties against 11 bacterial isolates and 1 fungal isolate. The largest inhibition zone (53 mm) was measured against A. baumannii while the smallest inhibition zone (26 mm) was recorded against S. aureus. Minimum inhibitory concentration (MIC) values were < 1 µg/ml for all microbes. However, the synthesized nanoparticles did not reveal synergism with any of the selected antibiotics (FICI values > 1). Nanoparticles possessed potent anti-biofilm powers with maximum (77%) inhibition of E. coli biofilms and minimum (45%) inhibition of S. enterica biofilms. Photocatalytic activity of Cr2O3 nanoparticles was evaluated to determine their efficacy in environmental bioremediation. Outcomes demonstrated degradation of methyl red (84%) but not of methylene blue dye. Furthermore, the Cr2O3 nanoparticles displayed considerable antioxidant (43%) as well as anti-inflammatory (44%) potentials. Hence, the present study accounts for the versatile applications of P. emblica-mediated Cr2O3 nanoparticles which could be pursued for future biomedical and environmental applications.