Spherical CeO2 nanoparticles encapsulated with Nelumbo nucifera Gaertn. flower extract and its in vitro anticancer activity against HCT 116 human colon cancer cell line

Abstract

The green synthesis of Cerium oxide nanoparticles (CeO₂ NPs) has been carried out using Nelumbo nucifera flower extract as capping and reducing agent. Optical property is determined using Ultra Violet-Visible spectroscopy (UV-Vis). From the Fourier Transform infrared spectroscopy (FTIR), characteristic peak at 506 cm^-1 confirms the presence of Ce-O bond. The fluorite-type cubic structure is confirmed by using FT-Raman spectroscopy. The crystalline phases are identified using powder X-Ray Diffractometer (PXRD). The stability and particle size of CeO₂ NPs is interpreted using Dynamic light Scattering (DLS) analysis. The particle size, shape and surface texture is analysed using High Resolution Scanning Electron Microscope (HRSEM) and High Resolution Transmission Electron Microscope (HRTEM) techniques. Selected Area Electron Diffraction (SAED) pattern confirms the identity of crystalline phases with the P-XRD data. Elemental mapping is done by using Energy Dispersive X-ray (EDX) analysis. Thermal behaviour of the CeO₂ NPs is analysed using the Thermo Gravimetric-Differential Thermal Analyser (TG-DTA) technique. The in vitro cytotoxic effect of CeO₂ NPs is tested against HCT 116 human colon cancer cell line using MTT assay. It is recorded that, IC50 of the CeO₂ NPs was 41.60 µg/mL. 62% of cell viability is minimized at 40 µg/mL in 46 h. This result enhances the importance of using greener eco-friendly method for synthesizing CeO₂ NPs with effective anticancer activity.