Using metal complex-labeled peptides for charge transfer-based biosensing with semiconductor quantum dots

2009 ◽  
Author(s):  
Igor L. Medintz ◽  
Thomas Pons ◽  
Scott A. Trammell ◽  
Juan B. Blanco-Canosa ◽  
Philip E. Dawson ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Charge Transfer ◽  
Metal Complex ◽  
Semiconductor Quantum Dots

scholarly journals Size-Dependent Non-FRET Photoluminescence Quenching in Nanocomposites Based on Semiconductor Quantum Dots CdSe/ZnS and Functionalized Porphyrin Ligands

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Eduard I. Zenkevich ◽  
Thomas Blaudeck ◽  
Alexander Milekhin ◽  
Christian von Borczyskowski
Keyword(s):  
Quantum Dots ◽  
Charge Transfer ◽  
Semiconductor Quantum Dots ◽  
Trap States ◽  
Quenching Rate ◽  
Time Resolved ◽  
Exciton Wave Function ◽  
Electron Hole Pair ◽  
Colloidal Semiconductor ◽  
Pl Quenching

We review recent experimental work to utilize the size dependence of the luminescence quenching of colloidal semiconductor quantum dots induced by functionalized porphyrin molecules attached to the surface to describe a photoluminescence (PL) quenching process which is different from usual models of charge transfer (CT) or Foerster resonant energy transfer (FRET). Steady-state and picosecond time-resolved measurements were carried out for nanocomposites based on colloidal CdSe/ZnS and CdSe quantum dots (QDs) of various sizes and surfacely attached tetra-mesopyridyl-substituted porphyrin molecules (“Quantum Dot-Porphyrin” nanocomposites), in toluene at 295 K. It was found that the major part of the observed strong quenching of QD PL in “QD-Porphyrin” nanocomposites can neither be assigned to FRET nor to photoinduced charge transfer between the QD and the chromophore. This PL quenching depends on QD size and shell and is stronger for smaller quantum dots: QD PL quenching rate constants scale inversely with the QD diameter. Based on the comparison of experimental data and quantum mechanical calculations, it has been concluded that QD PL quenching in “QD-Porphyrin” nanocomposites can be understood in terms of a tunneling of the electron (of the excited electron-hole pair) followed by a (self-) localization of the electron or formation of trap states. The major contribution to PL quenching is found to be proportional to the calculated quantum-confined exciton wave function at the QD surface. Our findings highlight that single functionalized molecules can be considered as one of the probes for the complex interface physics and dynamics of colloidal semiconductor QD.

Semiconductor Quantum Dots for Multicolor Fluorescence Imaging and Spectroscopy of Single Cancer Cells

2003 ◽  
Vol 773 ◽  
Author(s):  
Xiaohu Gao ◽  
Shuming Nie ◽  
Wallace H. Coulter
Keyword(s):  
Quantum Dots ◽  
Cancer Cells ◽  
Fluorescence Imaging ◽  
Organic Dyes ◽  
Fluorescent Proteins ◽  
Single Cells ◽  
Quantitative Imaging ◽  
Semiconductor Quantum Dots ◽  
Single Cancer ◽  
Imaging And Spectroscopy

AbstractLuminescent quantum dots (QDs) are emerging as a new class of biological labels with unique properties and applications that are not available from traditional organic dyes and fluorescent proteins. Here we report new developments in using semiconductor quantum dots for quantitative imaging and spectroscopy of single cancer cells. We show that both live and fixed cells can be labeled with multicolor QDs, and that single cells can be analyzed by fluorescence imaging and wavelength-resolved spectroscopy. These results raise new possibilities in cancer imaging, molecular profiling, and disease staging.

Hot Topic and Challenge of Semiconductor Quantum Dots as Fluorescence Labels*

2010 ◽  
Vol 37 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Chang-Yan LI ◽  
Qian LI ◽  
Hai-Tao LIU ◽  
Jun ZHANG ◽  
DAMIRIN Aletangaole
Keyword(s):  
Quantum Dots ◽  
Semiconductor Quantum Dots
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