Tracking the Single-Carbon-Dot Transmembrane Transport by Force Tracing Based on Atomic Force Microscopy.

Carbon dots (CDs) evoke a great deal of attention in biomedicine because of their unique properties. As an emerging theranostic agent, the CDs transmembrane transport process is the first and the most important step. Herein, a transmembrane dynamic process of transporting single CDs with folic acid into normal cells (Vero) and cancer cells (HeLa) were tracked by means of a force tracing technique based on atomic force microscopy. Meanwhile, the kinetic parameters of the the transmembrane process were measured and calculated. Interestingly, in the comparison between cancer cells (HeLa) and normal cells (Vero), the transporting force of single CDs with folic acid was smaller and the transporting average speed was slower.