Folic acid functionalized gadolinium-doped carbon dots as fluorescence / magnetic resonance imaging contrast agent for targeted imaging of liver cancer

Gadolinium-doped carbon dots (Gd-CDs), as a new class of nanomaterial, has a wide application prospect in targeted imaging and monitoring diagnosis and treatment of liver cancer because of their good fluorescence (FL)-magnetic resonance (MR) imaging properties. First, Gd-CDs were synthesized by hydrothermal method with gadodiamide as gadolinium source, citric acid as carbon source and silane coupling agent (KH-792) as coupling agent with FL quantum yield (QY) of 48.2%. Then, folic acid (FA), which is highly expressed in liver cancer, was used as a targeting component to modify Gd-CDs to obtain targeted imaging agent (Gd-CDs-FA). The results showed that Gd-CDs and Gd-CDs-FA have low cytotoxicity and good biocompatibility, and the targeting and selectivity of Gd-CDs-FA to HepG