Single-step synthesis of self-assembled carbon dots for enhanced cancer cell retention and theranostics applications

Photothermal therapy is a promising strategy for killing cancer cells, yet the use of carbon dots as a photothermal agent has limited its use due to the high excretion rate from the cancer cell due to its smaller size of less than 10 nm. In this study, we have developed a strategy for synthesizing self-assembled carbon dots with higher photothermal and lesser excretion from cells. Single-step synthesis of self-assembled carbon dots using thermal degradation method process using lecithin as carbon source. The self-assembly of lecithin-derived carbon dots is induced in the presence of water molecules. Excitingly, lecithin-derived self-assembly of carbon dots (LDSCD) shows superior photothermal efficacy even at low concentrations and fluorescence is red-shifted. Moreover, the LDSCD exhibits higher phototoxicity on incubation with cancer cells for two hours followed by near-infrared light exposure after twenty-four hours. The confocal images of the cells incubated with lecithin-derived selfassembly of carbon dots at two-time intervals (4 and 24 hrs) demonstrated higher retention of self-assembled quantum dots compared to the smaller-size carbon dots (<50 nm).