Carbon dots derived from Beta vulgaris: evaluation of its potential as antioxidant and anticancer agent

Carbon dots (CDs) endowed with outstanding physico-chemical characteristics expeditiously garnered tremendous popularity in the scientific community. CDs can be synthesized from a variety of natural resources and can replace metal semiconductor quantum dots in the range of applications such as bio-imaging, sensing and catalysis. Herein, CDs are green synthesized from Beta vulgaris via a single step hydrothermal approach (b-CDs). The synthesized carbon dots are characterized using UV-visible spectrophotometry, Fluorescence spectroscopy, High resolution transmission electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction technique (XRD) and Raman spectroscopy. The b-CDs hence developed exhibited the signature 'excitation-dependent fluorescence emission' with its most intense emission in the green region. The quantum yield for the b-CDs obtained by this synthetic approach evinced an appreciable value of 11.6%. The antioxidant property of b-CDs are evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay to obtain a maximum scavenging activity of 94.5% at a concentration of 1000 mu g ml(-1) and its underlying mechanisms are illustrated. The blood compatibility of b-CDs are assessed using haemolysis assay and the cytotoxicity evaluated using MTT assay shows significant cell growth-inhibition against the human breast cancer (MCF-7) and hepatocellular carcinoma (HepG2) cell lines. This succinct study demonstrates the inherent therapeutic potential of biocompatible carbon dots.