### (NH4)2MoS4引导CdTe QDs自组装及光学性质调控和细胞成像

1. 苏州大学材料与化学化工学部 苏州 215123
• 投稿日期:2017-09-19 发布日期:2017-11-06
• 通讯作者: 马楠 E-mail:nan.ma@suda.edu.cn
• 基金资助:

项目受国家自然科学基金（Nos.21175147，91313302，21475093）、国家高技术研究发展计划（863计划，No.2014AA020518）和青年千人计划项目资助.

### (NH4)2MoS4-Guided Self-Assembly of CdTe QDs and Control over Their Optical Properties and Cell Imaging

Sun Quanhong, Li Zhi, Ma Nan

1. College of Chemistry, Chemical Engineering and Materials Science of Soochow University, Suzhou 215123
• Received:2017-09-19 Published:2017-11-06
• Contact: 10.6023/A17090428 E-mail:nan.ma@suda.edu.cn
• Supported by:

Project supported by the National Natural Science Foundation of China (Nos. 21175147, 91313302, 21475093), the National High Technology Research and Development Program of China (863 Program, No. 2014AA020518) and the Thousand Youth Talents Plan.

Conventionally, red shift of QD photoluminescence (PL) could be achieved by growing QDs to larger sizes using hydrothermal method, which is usually a very slow process. We synthesized green fluorescent CdTe quantum dots with GSH as the ligand and proved the successful synthesis of (NH4)2MoS4 by UV-Vis, X-Ray Diffraction, Raman spectroscopy. In the process of research, we found that (NH4)2MoS4 can change the wavelength of CdTe quantum dots under the condition of heating or at room temperature. Redshift of emission wavelength can change with the different ratio between (NH4)2MoS4and CdTe QDs. In this study, we report a rapid and convenient method to achieve red-shift of CdTe QD PL via (NH4)2MoS4-guided QD self-assembly. We show that the emission wavelength of CdTe QDs underwent a red-shift of more than 100 nm for 15 min at 100℃ in the presence of (NH4)2MoS4. At the same time, we conduct a experiment, which have no red-shift in the absence of (NH4)2MoS4 for 15 min at 100℃. This illustrates that the (NH4)2MoS4 plays an important role in CdTe QDs self-assembly. The red-shift of QD PL was also observed at room temperature but relatively slower. The formation of QD assembly was confirmed by gel electrophoresis, transmission electron microscopy, and X-ray photoelectron spectroscopy. The result of gel electrophoresis and transmission electron microscopy directly shows the self-assembly morphology of CdTe QDs and the change of size and shape. Self-assembly entity was proved to contain Mo and Cd by the X-ray photoelectron spectroscopy, which confirmed the connection between (NH4)2MoS4and CdTe QDs. A control experiment was conducted by replacing (NH4)2MoS4with Na2S for QD assembly, in that case no apparent change of emission wavelength was observed. These results reveal that MoS42- within (NH4)2MoS4 is crucial for self-assembly of CdTe QDs. Accordingly, we propose a reasonable model of (NH4)2MoS4-guided CdTe QD self-assembly. In this model, we consider the connection between a (NH4)2MoS4 and two CdTe QDs in ideal condition. With the increasing ratio of (NH4)2MoS4, much more connection between (NH4)2MoS4 and CdTe will be obtained. Assembling entity morphology changed with different cross-linking way. The resulting QD assembly was further applied to cell imaging experiments, demonstrating their potentials in this field.