Facile Green Synthesis Approach for the Production of Super-Paramagnetic Fe3o4 Nanoflakes and Their Antimicrobial Activity

Abstract

Green vegetables are used in our daily life and are essential part of our daily food. Green vegetables provide us different vitamins, chlorophyll, and nutrients which make them strong candidate against different diseases and bacterial infection. The efficacy of these green vegetables becomes higher when added in body compatible compounds e.g., iron oxide. In this research article iron oxide (magnetite, Fe3O4) nanoflakes are synthesized using green synthesis method. Iron nitrate was used as precursor which is mixed in De-ionized water. Three different green vegetables (Spinach, Broccoli and Pumpkin) dried powder was added in aqueous solution of iron nitrate. X-ray diffraction (XRD) results confirm the formation of phase pure Fe3O4 specifically in case of spinach. Spinach, pumpkin, and broccoli powder act as reducing agent and do not form any secondary phase of iron oxide. Retvield refined patterns of Spinach, Broccoli and Pumpkin reveals the perfect matching with standard data. Crystallite size of magnetite nanoflakes is in the range of 47–59 nm. The value lattice parameters are increased with the decrease in crystallite size for different plant extracts. Relatively higher x-ray density has been observed in case of spinach extract which proves the large area and dense growth of nanoflakes as observed in SEM images. FTIR analysis shows the formation of two bands at 478 and 590cm-1 are corresponding to Fe-O stretching of bulk Fe3O4. FTIR spectrum of spinach powder shows a band at446cm−1 which is typical for Fe–O. Presence of Fe-O bond in spinach reveals that spinach extract strengthen the Fe3O4 phase as observed in XRD data.UV-Vis spectra exhibit a strong absorption peak at 280nm due to the absorption along with scattering of light by Fe3O4. Magnetization − hysteresis (MH) curve of the sample acquired at room temperature. Fe3O4 with spinach extract possesses relatively low saturation magnetization (Ms)~ 66emu/g as compared to pumpkin (105emu/g) and broccoli (130emu/g) additives with negligible coercivity (~25Oe), which is the characteristic of superparamagnetic materials. SEM images are representing the formation of plentiful nanoflakes. The size of Fe3O4 nanoflakes is multi-dispersed, ranging from tens hundreds to few hundred of nanometers (300 nm) and length is greater than 5μm. Nanoflakes obtained here are larger than in length with E. Coli bacteria that improves the adhesion of E. coli to its surface. Antibacterial study shows that these synthesized Fe3O4 nanoflakes are highly effective against E. Coli bacteria and produce 32mm zone of inhibition.

Keywords: Green Synthesis, Fe3O4, Spinach, Pumpkin, Broccoli, Antibacterial