Green-synthesised cerium oxide nanostructures (CeO-NS) show excellent biocompatibility for phyto-cultures as compared to silver nanostructures (Ag-NS)

The use of nanostructures (NS) in plant tissue culture can be beneficial only if we have their complete bio-safety and biocompatibility profile. In the recent past, increasing rate of NS-cytotoxicity has alarmed the plant biotechnologist to think critically. Keeping this in view, our current study represents a comparative cytotoxicity examination of green fabricated highly potent CeO-NS and Ag-NS. Phyto-reductants from O. europaea extract simultaneously acted as reducing as well as capping agent in tuning the shape of CeO-NS and Ag-NS to as small as 18 nm and 26 nm respectively. High-performance liquid chromatography (HPLC) analysis of O. europaea extract supplemented by thermo-gravimetric analysis (TGA) findings further validates the capping action of bioactive agents from the plant extract. X-ray diffraction (XRD) testing confirms the phase purity and crystalline nature of prepared CeO-NS and Ag-NS. Fourier transform infrared (FTIR) spectroscopy shows typical Ce-O bond vibrations at 457 cm and Ag around 563 cm to 641 cm. Moreover, the optimized NS shows differential cytotoxicity when tested on callogenesis and organogenesis of Lycopersicon esculentum. Findings from DPPH assay shows that CeO-NS are biocompatible and have tremendously enhanced the antioxidant potential of L. esculentum with greater biomass, contrastingly Ag-NS are found phyto-toxic with lower antioxidant potential and have a negative impact when added during plant tissue culture.