Poria cocos-derived carbon dots for cellular imaging, free radical scavenging and pH sensing

Green, economical preparation of carbon dots (CDs) from traditional Chinese herbal medicine Poria cocos via a one-step hydrothermal treatment was reported. The CDs exhibited excellent aqueous dispersibility, superior photoluminescence (PL) property and low cytotoxicity. Taking advantage of these properties, CDs were demonstrated as excellent multicolor bioimaging agents for the cellular imaging of MDA-MB-435S cells, with main distributions in the cell membranes and cytoplasm. Moreover, the CDs also exhibited good radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) thanks to their inheritance of characteristic functionalities from Poria cocos. Lastly, our study also shown that the PL of CDs was reversibly sensitive to pH in the range of 4.0 and 9.0, and a highly sensitive pH-sensing assay was developed exploiting this phenomenon. In summary, the study opened up new development paths for the modernization and vitalization of traditional Chinese medicine in biomedical research.