文献类型：期刊文献

英文题名：Coenzyme Q Functionalized CdTe/ZnS Quantum Dots for Reactive Oxygen Species (ROS) Imaging

作者：Qin, Li-Xia[1,2];Ma, Wei[1,2];Li, Da-Wei[1,2];Li, Yang[1];Chen, Xiaoyuan[3];Kraatz, Heinz-Bernhard[4];James, Tony D.[5];Long, Yi-Tao[1,2]

机构：[1]E China Univ Sci & Technol, Shanghai Key Lab Funct Mat Chem, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Dept Chem, Shanghai 200237, Peoples R China;[3]NIH, Lab Mol Imaging & Nanomed LOMIN, Bethesda, MD 20892 USA;[4]Univ Western Ontario, Dept Chem, London, ON N5A 5B9, Canada;[5]Univ Bath, Dept Chem, Bath BA2 7AY, Avon, England

年份：2011

卷号：17

期号：19

起止页码：5262

外文期刊名：CHEMISTRY-A EUROPEAN JOURNAL

收录：;EI(收录号：20111713933096);WOS:【SCI-EXPANDED(收录号:WOS:000290214200009)】；

基金：This work was support by the Major Research Plan of the National Natural Science Foundation of China (Grant No. 91027035), Shanghai Pujiang Program Grant of China (Grant No. 09 J1403300) and the Ministry of Health of China (Grant No. 2009ZX10004-301). This research was also partly funded by the National Science and Engineering Research Council of Canada. We also thank the Catalysis and Sensing for our Environment (CASE) consortium for networking opportunities.

语种：英文

外文关键词：coenzyme Q; electrochemistry; fluorescence; quantum dots; reactive oxygen species

摘要：Quantum dots (QDs) have been widely used for fluorescent imaging in cells. In particular, surface functionalized QDs are of interest, since they possess the ability to recognize and detect the analytes in the surrounding nanoscale environment based on electron and hole transfer between the analytes and the QDs. Here we demonstrate that fluorescence enhancement/quenching in QDs can be switched by electrochemically modulating electron transfer between attached molecules and QDs. For this purpose, a number of redox-active coenzyme Q (CoQ) disulfide derivatives [CoQCnS](2) were synthesized with different alkyl chain lengths (n = 1, 5, and 10). The system supremely sensitive to NADH ( nicotinamide adenine dinucleotide) and superoxide radical (O2C center dot-), and represents a biomimetic electron-transfer system, modeling part of the mitochondrial respiratory chain. The results of our in situ fluorescence spectroelectro-chemical study demonstrate that the reduced state of [ CoQCnS] 2 significantly enhanced the fluorescence intensity of CdTe/ZnS QDs, while the oxidized state of the CoQ conjugates quench the fluorescence to varying degrees. Fluorescence imaging of cells loaded with the conjugate QD-[CoQCnS](2) displayed strikingly differences in the fluorescence depending on the redox state of the capping layer, thus introducing a handle for evaluating the status of the cellular redox potential status. Moreover, an MTT assay (MTT=3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) proved that the cytotoxicity of QDs was significantly reduced after immobilization by CoQ derivatives. Those unique features make CoQ derivatived QDs as a promising probe to image redox coenzyme function in vitro and in vivo.