Biocompatible carbon nanodots from red onion peels for anti-oxidative and bioimaging applications

Abstract

The present study reports the green synthesis of carbon dots (C-dots) by one-step, facile hydrothermal process, using red onion peels as the base material. The optical properties of the C-dots have been studied in detail using UV-Visible spectroscopy, fluorescence spectroscopy, and quantum yield measurements. The structural and compositional analysis of fluorescent C-dots was done via X-ray diffraction (XRD) and transmission electron microscopy (TEM). Surface chemistry of the C-dots was studied using Fourier transform infrared spectroscopy (FTIR). The stability measurement of C-dots was done via Zeta potential. The biocompatibility of the C-dots was evaluated using a breast cancer cell line (MCF-7). C-dots were used as potential bioimaging agents for fluorescence imaging of mammalian cell lines. Concentration-dependent cellular uptake of the C-dots by the MCF-7 cells was shown qualitatively using fluorescence microscopy. The study also assessed the antioxidant activity of the C-dots. Thus, this work validates the red onion peel-derived C-dots as excellent bioimaging and antioxidant agents for mammalian cell lines.