Bioinspired multicolor carbon dots: A comprehensive cytotoxicity, phytotoxicity and bioimaging in animal cells and plants.

Abstract

During past decades, carbon dots (CDs) as a kind of nanoparticles with interesting fluorescence properties have retained their place as one of the best bioimaging agents although their effects on plants have been rarely studied. In this study, we synthesized two kinds of concentration-dependent multicolor CDs with two solvent approaches, phosphate buffered saline (PBS) and Ethanol 20%. We confirm the nature of CDs through Fourier transform infrared spectroscopy, atomic force microscopy, dynamic light scattering, zeta potential, X-ray powder diffraction, and high-resolution transmission electron microscopy. Afterward, cytotoxicity, phytotoxicity, and bioimaging of animal cells and plants by both synthesized CDs have been examined. Eventually, PBS-based CDs were recommended during this study as an efficient bioimaging agent for animal cells and plants because of appealing features of this CD, such as a small size range of less than 10 nm, surface charge with average of -24 mV, a high quantum yield of 35.82%, the higher fluorescence intensity of approximately 400 a.u. for blue fluorescence light and 250 a.u. for green fluorescence light. Other features showing the superiority of PBS-based CDs include high photostability, low phytotoxicity (P≤0.05 and P≤0.01) and above all, there is no significant cytotoxicity at the concentration range of 500-7.81 μg/mL.