Engineering iodine-doped carbon dots as dual-modal probes for fluorescence and X-ray CT imaging

Abstract

Miaomiao Zhang,1,* Huixiang Ju,2,* Li Zhang,1,* Mingzhong Sun,2 Zhongwei Zhou,2 Zhenyu Dai,3 Lirong Zhang,1 Aihua Gong,1 Chaoyao Wu,1 Fengyi Du1 1School of Medicine, Jiangsu University, Zhenjiang, People’s Republic of China; 2Department of Clinical Laboratory, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, Jiangsu, People’s Republic of China; 3Radiology Department, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, Jiangsu, People’s Republic of China *These authors contributed equally to this work Abstract: X-ray computed tomography (CT) is the most commonly used imaging technique for noninvasive diagnosis of disease. In order to improve tissue specificity and prevent adverse effects, we report the design and synthesis of iodine-doped carbon dots (I-doped CDs) as efficient CT contrast agents and fluorescence probe by a facile bottom-up hydrothermal carbonization process. The as-prepared I-doped CDs are monodispersed spherical nanoparticles (a diameter of ~2.7 nm) with favorable dispersibility and colloidal stability in water. The aqueous solution of I-doped CDs showed wavelength-dependent excitation and stable photoluminescence similar to traditional carbon quantum dots. Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility. After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance. These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis. Keywords: carbon dots, contrast agents, iodine-doped, CT imaging