Green-synthesized Nickel oxide nanoparticles: Magnetic and biomedical applications

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 gramnegative bacteria is more defiant of antibiotic drugs than gram-positive bacteria.

Automated summary

In this study, cubic nickel oxide nanoparticles were synthesized using Calotropis gigantea leaf extract as a fuel. The characterization techniques confirmed the formation of crystalline nickel oxide nanoparticles with an average size of 17.06 nm. The nanoparticles exhibited hexagonal shape and agglomeration. Optical studies showed an energy bandgap of 3.04 eV and FTIR analysis confirmed the vibrational stretching mode of Ni-O. The nanoparticles also demonstrated room temperature ferromagnetic property and significant anticancer activity against liver cancer cells. Additionally, the antibacterial assay indicated higher resistance of gram-negative bacteria to antibiotic drugs compared to gram-positive bacteria.