TY - JOUR
T1 - Coenzyme Q functionalized CdTe/ZnS quantum dots for reactive oxygen species (ROS) imaging
AU - Qin, Li Xia
AU - Ma, Wei
AU - Li, Da Wei
AU - Li, Yang
AU - Chen, Xiaoyuan
AU - Kraatz, Heinz Bernhard
AU - James, Tony D.
AU - Long, Yi Tao
PY - 2011/5/2
Y1 - 2011/5/2
N2 - 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 (O 2 .-), and represents a biomimetic electron-transfer system, modeling part of the mitochondrial respiratory chain. The results of our in situ fluorescence spectroelectrochemical 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. Biomimetic electron transfer: An in situ fluorescence spectroelectrochemical study demonstrates that the reduced state of [CoQCnS]2 significantly enhanced the FL intensity of CdTe/ZnS QDs, while the oxidized state of the coenzyme Q conjugates quench the fluorescence to varying degrees. The system is supremely sensitive to NADH and superoxide radical (O2 . -), and represents a biomimetic electron-transfer system modeling part of the mitochondrial respiratory chain.
AB - 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 (O 2 .-), and represents a biomimetic electron-transfer system, modeling part of the mitochondrial respiratory chain. The results of our in situ fluorescence spectroelectrochemical 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. Biomimetic electron transfer: An in situ fluorescence spectroelectrochemical study demonstrates that the reduced state of [CoQCnS]2 significantly enhanced the FL intensity of CdTe/ZnS QDs, while the oxidized state of the coenzyme Q conjugates quench the fluorescence to varying degrees. The system is supremely sensitive to NADH and superoxide radical (O2 . -), and represents a biomimetic electron-transfer system modeling part of the mitochondrial respiratory chain.
KW - coenzyme Q
KW - electrochemistry
KW - fluorescence
KW - quantum dots
KW - reactive oxygen species
UR - https://www.scopus.com/pages/publications/79954990327
U2 - 10.1002/chem.201003749
DO - 10.1002/chem.201003749
M3 - 文章
C2 - 21503990
AN - SCOPUS:79954990327
SN - 0947-6539
VL - 17
SP - 5262
EP - 5271
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 19
ER -