Spinel ZnCr₂O₄ nanorods synthesized by facile sol-gel auto combustion method with biomedical properties

In this study, spinel zinc chromite nanorods (ZnCr₂O₄ NRs) were successfully manipulated by a simple sol-gel auto combustion process employing urea as fuel. The sample was only required to sinter at 500 °C for 2 h to obtain the single crystalline phase. The phase formation, crystallinity, and surface topography of synthesized ZnCr₂O₄ NRs were explored by X-ray diffraction (XRD), UV-Vis reflectance spectroscopy (UVDRS), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) spectroscopy, and vibrating sample magnetometry (VSM). XRD analysis confirms the formation of spinel ZnCr₂O₄ NRs. The FTIR spectrum displays the two vibrational peaks of Cr-O, and Zn-O at 489 and 615 cm^-1, correspondingly. These vibrational bonds were correlated with ZnCr₂O₄ and revealed the production of cubic spinel ZnCr₂O₄ NRs. FESEM indicates the presence of hexagonal-rod-shaped particles. EDX spectrum demonstrates the elemental composition of the ZnCr₂O₄ NRs and confirms the primary peak of Zn, Cr, and O. The obtained ZnCr₂O₄ NRs exhibit an antiferromagnetic behavior. The bandgap energy of ZnCr₂O₄ NRs was ascertained and was shown to be 3.45 eV. Furthermore, the antifungal and antibacterial effect of ZnCr₂O₄ NRs was examined against pathogenic strains by disc diffusion technique. Besides these, the antimalarial activity of ZnCr₂O₄ NRs was studied against Plasmodium falciparum. Thus, the as-synthesized ZnCr₂O₄ NRs showed significant antibacterial, antifungal and antimalarial activity and may be helpful for research opening a novel horizon in nanomedicine. Graphical abstract.