Superior reducing carbon dots from proanthocyanidin for free-radical scavenging and for cell imaging

The presence of excessive ROS can cause much harm to the human body and can even cause diseases. Therefore, it is important to detect and remove ROS, but there is no ideal method available for this at present. In this research, using procyanidins, a type of plant extract with strong reducibility, as raw materials, fluorescent carbon dots (CDs) were prepared by a hydrothermal method. The proanthocyanidin-based carbon dots (PCDs) emit a light-green colored light under UV irradiation. The PCDs retain the strong reducibility of procyanidins and are highly water-soluble compared with procyanidins. The PCDs, in addition to having good biocompatibility, also have the superior properties of radical scavenging activity and cell imaging. In in vitro experiments, 1,1-diphenyl-2-picrylhydrazyl (DPPH; 100 mu M) was reduced by 30% when PCDs were added up to a concentration of 87.5 mu g mL(-1). At the same time, the fluorescence quenching correlates with the concentration of hypochlorite and hydrogen peroxide and has a good linearity in the range of 250-2250 nM and 60-180 mu M with a detection limit of 3.676 nM and 0.602 mu M, respectively. Based on the previously described advantages, PCDs have potential as a biomedicine.

Automated summary

This research utilized procyanidins to prepare fluorescent carbon dots (PCDs) with strong reducibility and high water solubility, which can scavenge radicals and image cells. Experimental results indicate that PCDs have the potential to be a biomedicine.