Physics Department, Faculty of Science, Yazd University, P.O. Box 89195-741, Yazd, Iran.
Radiation Application Research School, Nuclear Science and Technology Research Institute (NSTRI), Moazzen Blvd., Rajaeeshahr, P.O. Box 31485-498, Karaj, Iran.
J Fluoresc. 2021 May;31(3):897-906. doi: 10.1007/s10895-021-02720-5. Epub 2021 Mar 27.
This research reports the preparation and examination of Cadmium Telluride (CdTe) Quantum Dots and doping CdTe QDs with Europium (Eu), Gadolinium (Gd), and Manganese (Mn) prepared in aqueous solution using TGA as a capping agent. Magnetic QDs (MQDs) are important agents for fluorescence (FL) /magnetic resonance (MR) dual-modal imaging due to their excellent optical and magnetic properties. Herein, the chemical bonds, structural, fluorescence, and magnetized properties of CdTe QDs and effect of Mn, Eu, and Gd ions doping on their properties were examined by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTM), Energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL), Ultraviolet-visible spectroscopy (UV-Vis), and vibrating sample magnetometer measurements (VSM). Almost similar X-Ray patterns with the absence/presence of ions for all samples with cubic crystal structures were obtained which indicated that the introduction of ions into CdTe QDs could not alter the cubic primary structure of CdTe. Monodisperse size distributed with seemingly-spherical shapes, and also, the estimated mean diameters about 3 and less than 3 nm of QDs were obtained. The effect of X ions injection on the fluorescence and UV-Vis properties of the QDs were also investigated. Optical studies showed the decreases in bandgap as the heating time increases during synthesis while undergoing red-shift. The CdTe nanocrystals with high PL quantum yields were achieved in more than 6 h of heating. Also, investigations have shown the quenching of fluorescence by the existence of ions in the CdTe QDs. Then, all the ions doped QDs exhibited ferromagnetic behavior at room temperature by a vibrating sample magnetometer which confirmed the success of the presentation of ions into CdTe cubic crystal structure. They can have been employed as a suitable contrast agent successfully for biological applications such as FL/MR dual-modal imaging.
本研究报告了使用热重分析（TGA）作为封端剂在水溶液中制备碲化镉（CdTe）量子点并掺杂铕（Eu）、钆（Gd）和锰（Mn）的方法，并对其进行了制备和研究。磁性量子点（MQDs）由于其优异的光学和磁学性质，是荧光（FL）/磁共振（MR）双模成像的重要造影剂。在此，通过 X 射线粉末衍射（XRD）、高分辨率透射电子显微镜（HRTEM）、能谱（EDX）、傅里叶变换红外光谱（FTIR）、光致发光光谱（PL）、紫外-可见光谱（UV-Vis）和振动样品磁强计（VSM）研究了 CdTe QDs 的化学键、结构、荧光和磁化性质，以及 Mn、Eu 和 Gd 离子掺杂对其性质的影响。所有样品均获得具有立方晶体结构的几乎相似的 X 射线图谱，表明离子的引入不会改变 CdTe QDs 的立方基态结构。通过单分散尺寸分布，获得了看似球形的形状，并且还获得了 QDs 的约 3nm 和小于 3nm 的平均直径。还研究了 X 离子注入对 QDs 的荧光和 UV-Vis 性质的影响。光学研究表明，在合成过程中，随着加热时间的增加，带隙减小，同时发生红移。在超过 6 小时的加热时间内，CdTe 纳米晶获得了较高的 PL 量子产率。此外，研究表明，离子的存在会使 CdTe QDs 的荧光猝灭。然后，所有掺杂离子的 QDs 在室温下通过振动样品磁强计表现出铁磁行为，这证实了离子成功地进入了 CdTe 立方晶体结构。它们可以成功地用作生物应用的合适造影剂，例如 FL/MR 双模成像。
