Employing one-step hydrothermal treatment of o-phenylenediamine and lysine to exploit their self- and copolymerization, four kinds of CDs (ECDs, NCDs, GCDs, and LCDs) are synthesized, possessing different surface groups (CH3, C-O-C, NH2, and COOH) and lipophilicity which endow them with various uptake pathways to achieve tunable organelle imaging. Specifically, highly lipophilic ECDs with CH3 group and NCDs with C-O-C group select passive manner to target to endoplasmic reticulum and nucleus, respectively. Amphiphilic GCDs with CH3, C-O-C and NH2 groups prefer caveolin-mediated endocytosis to locate at Golgi apparatus. Highly hydrophilic LCDs with CH3, NH2 and COOH groups are involved in clathrin-mediated endocytosis to localize in lysosomes. Besides, imaging results of cell division, three-dimensional reconstruction and living zebrafish demonstrate that the obtained CDs are promising potential candidates for specific organelle-targeting imaging.
Keywords: carbon dots; lipophilicity; organelle imaging; surface group; uptake pathways.