Facile synthesis of Gd-doped CdTe quantum dots with optimized properties for optical/MR multimodal imaging

• Published in: Journal of biological inorganic chemistry 2017-12, Vol.22 (8), p.1151-1163
• Main Authors: Li, Zizhen, Dergham, Ali, McCulloch, Holly, Qin, Yubo, Yang, Xiuying, Zhang, Jingchang, Cao, Xudong
• Format: Article
• Language: English
• Subjects: Animals; Axons - metabolism; Biochemistry; Biocompatibility; Biomedical and Life Sciences; Cadmium Compounds - chemistry; Chemistry Techniques, Synthetic; Dextran; Gadolinium - chemistry; Hydrogen-Ion Concentration; Inorganic chemistry; Life Sciences; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Mice; Microbiology; Multimodal Imaging - methods; NIH 3T3 Cells; NMR; Nuclear magnetic resonance; Optical Imaging - methods; Optical properties; Original Paper; Quantum dots; Quantum Dots - chemistry; Tellurium - chemistry
• ISSN: 0949-8257; 1432-1327
• DOI: 10.1007/s00775-017-1491-y

Each imaging modality has its own merits and intrinsic limitations; therefore, combining two or more complementary imaging modalities has become an interesting area of research. Recently, magnetic ion-doped quantum dots have become an increasingly promising class of optical/magnetic resonance multimodal imaging probes due to their excellent physical and chemical properties. In this work, Gd-doped CdTe quantum dots (QDs) were successfully synthesized via a facile one-step refluxing route,and their optimal synthesis conditions were investigated. The prepared CdTe:Gd QDs were shown to exhibit good optical properties with high quantum yields up to 69%, high longitudinal relaxivity ( r 1  = 3.8 mM −1  s −1 ), and good crystalline structures. In addition, after further QD surface modification with dextran amine (DA), the resulting DA-modified QDs (i.e. DA–CdTe:Gd QDs) showed strong magnetic resonance imaging contrast ( r 1  = 3.5 mM −1  s −1 ) and improved biocompatibility when tested with cell cultures in vitro. Taken together, this new material demonstrated promising performances for both optical and magnetic resonance imaging modalities, suggesting its promising potential applications in non-invasive imaging, particularly in neuronal tracing.