Synthesis of Fluorescence/MRI Dual Targeted Imaging Theranostics Reagent

Poly (ethylene glycol diamine) (NH2-PEG-NH2) modified graphene quantum dots (GODs) were conjugated with diethylenetriaminepentaacetic acid (DTPA) via an amide bond. Then the product further coordinated with Gd3+ ions, followed by the subsequent linkage of folic acid (FA) to form FA/GODs-Gd(DTPA). Next, an anticancer drug, doxorubicin ( DOX), was loaded on the surface of FA/GODs-Gd(DTPA) to obtain the final fluorescence/MRI dual targeted imaging diagnostic reagents (FA/GODs-Gd(DTPA)/DOX) for lung cancer cells. The sample was characterized by transmission electron microscopy, UV-Vis absorption spectroscopy, fluorescence spectroscopy, laser confocal microscopy, and so on. Compared with normal HLF cells, the results of MRI, confocal laser scanning microscopy and MTT showed that the prepared FA/GODs-Gd(DTPA)/DOX could be targeted to detect lung cancer H460 cells, in which folate receptor was highly expressed, and also displayed significant anti-tumor activity.