Green-synthesized Nickel oxide nanoparticles: Magnetic and biomedical applications

Abstract

In this work, cubic Nickel oxide (NiO) nanoparticles (NPs) were prepared by a hotplate combustion process using Calotropis gigantea (crown flower) leaf extract as fuel. The synthesized NPs were characterized by analytical techniques like Powder X-ray diffraction (PXRD), UV–visible spectroscopy (UV–vis), Transmission electron microscope (TEM), Scanning electron microscope (SEM), and Vibrating sample magnetometer (VSM). PXRD results confirmed the formation of single-phase crystalline NiO NPs with an average crystallite size of 17.06 nm. Further, SEM and TEM analysis shows the formation of hexagonal-shaped NiO NPs with agglomeration. The energy bandgap of 3.04 eV was observed for the NiO NPs by optical studies. The vibrational stretching mode of Ni-O (431 cm−1) was validated by FTIR analysis. VSM studies reveal room temperature ferromagnetic property. The as-prepared NPs were subjected to a cytotoxicity test against liver cancer (HepG2) cell line using an MTT assay and significant anticancer activity was observed. Furthermore, an antibacterial assay indicates gram-negative bacteria is more defiant of antibiotic drugs than gram-positive bacteria.