Impact of Mn2+ substitution on physical and antibacterial properties of ZnFe2O4 nanoparticles

The sol–gel method is employed for the preparation of zinc ferrite nanoparticles. The effect of Mn2+ substitution on the morphological, structural, optical and magnetic properties of zinc ferrite nanoparticles was studied. X-ray diffraction and Fourier transform infrared spectroscopic analyses evidence the presence of cubic spinel structure with (mathrm{Fd}overline{3}mathrm{m }) space group. The average size of crystallites determined using the Scherrer formula for manganese-doped and pure zinc ferrite nanoparticles ranged from 7 to 20 nm. Purity and elemental composition were evidenced by energy dispersive X-ray analysis. The bandgap estimated from UV–visible spectra was 1.89–2.21 eV. The saturation magnetization (Ms), retentivity (Mr) and coercivity (Hc) were estimated from hysteresis curves of all samples that depicted ferromagnetic characteristics. The synthesized nanoparticles exhibited good antibacterial activity against both gram-positive (Lactobacillus and Staphylococcus aureus) and gram-negative (Vibrio cholerae and Pseudomonas aeruginosa) strains.