Fluorescent CDs@PCL hybrids via tartaric acid, CDs-cocatalyzed polymerization

•An efficient method is developed to obtain CDs with strong and stable photoluminescence.•Fluorescent carbon dots (CDs) were attached to CDs@PCL hybrids with excellent biocompatibility and biodegradability.•The CDs@PCL hybrids have a promising future in biomedicine, photocatalyst, bioimaging, and environmental analysis.

In this paper, the environment-friendly, water-soluble carbon dots (CDs) with stable photoluminescence (PL) have been prepared via the one-step pyrolysis of lotus leaf. Then the as-prepared CDs containing abundant hydroxylic and carboxylic groups were employed as cocatalyst with tartaric acid (TA) in ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). The low-toxic organic acid TA, as main catalyst, was used to catalyze the ROP of ε-CL efficiently. The fluorescent CDs@PCL hybrids were obviously hydrophobic and they exhibited an excellent biocompatibility, and biodegradability due to the existence of PCL. Therefore the hydrophobic, biodegradable and multi-color fluorescent CDs@PCL hybrids may have potential applications in biomedicine, photocatalyst, bioimaging, and environmental analysis. Furthermore the application of CDs in catalyzing and initiating polymerization reaction will exemplify the versatility of CDs in the most unexpected fields.