Saha Ajoy K, Sharma Parvesh, Sohn Han-Byul, Ghosh Siddhartha, Das Ritesh K, Hebard Arthur F, Zeng Huadong, Baligand Celine, Walter Glenn A, Moudgil Brij M
Particle Engineering Research Center, Materials Science and Engineering, University of Florida, Gainesville, FL 32611.
Department of Physics, University of Florida, Gainesville, FL 32611.
J Mater Chem B. 2013 Dec 7;1(45):6312-6320. doi: 10.1039/C3TB20859A.
A facile synthesis of 3-6 nm, water dispersible, near-infrared (NIR) emitting, quantum dots (QDs) magnetically doped with Fe is presented. Doping of alloyed CdTeS nanocrystals with Fe was achieved using a simple hydrothermal method. The magnetic quantum dots (MQDs) were capped with NAcetyl-Cysteine (NAC) ligands, containing thiol and carboxylic acid functional groups to provide stable aqueous dispersion. The optical and magnetic properties of the Fe doped MQDs were characterized using several techniques. The synthesized MQDs are tuned to emit in the Vis-NIR (530-738 nm) wavelength regime and have high quantum yields (67.5-10%). NIR emitting (738 nm) MQDs having 5.6 atomic% Fe content exhibited saturation magnetization of 85 emu/gm[Fe] at room temperature. Proton transverse relaxivity of the Fe doped MQDs (738 nm) at 4.7 T was determined to be 3.6 mMs. The functional evaluation of NIR MQDs has been demonstrated using phantom and studies. These water dispersible, NIR emitting and MR contrast producing Fe doped CdTeS MQDs, in unagglomerated form, have the potential to act as multimodal contrast agents for tracking live cells.
本文介绍了一种简便的合成方法，用于制备尺寸为3-6纳米、水分散性好、发射近红外（NIR）光且磁性掺杂铁的量子点（QDs）。采用简单的水热法实现了用铁对合金化的CdTeS纳米晶体进行掺杂。磁性量子点（MQDs）用含有巯基和羧酸官能团的N-乙酰半胱氨酸（NAC）配体进行封端，以提供稳定的水分散体。使用多种技术对铁掺杂MQDs的光学和磁性性质进行了表征。合成的MQDs被调谐到在可见-近红外（530-738纳米）波长范围内发射，并且具有高量子产率（67.5-10%）。铁含量为5.6原子%的发射近红外（738纳米）的MQDs在室温下表现出85 emu/gm[Fe]的饱和磁化强度。铁掺杂MQDs（738纳米）在4.7 T时的质子横向弛豫率被确定为3.6 mM⁻¹s⁻¹。使用模型和细胞研究证明了近红外MQDs的功能评估。这些水分散性好、发射近红外光且产生磁共振对比的铁掺杂CdTeS MQDs以未团聚的形式有潜力作为跟踪活细胞的多模态造影剂。
