Z. (Zijun) Wang MSc
z.wang1@uu.nl
Gegenereerd op 2017-06-23 14:15:37


    Quantum dots (QDs), semiconductor nanocrystals in a size range of 2-10 nm, have gained much interest in the last few years for molecular imaging purposes, due to their bright fluorescence, high photo-stability, and tunable emission. Especially II-VI QDs like CdSe and CdTe have been shown to be highly efficient, stable and versatile fluorescent probes but their use is limited by the presence of the highly toxic Cd. We aim at the development of non-toxic probes for molecular imaging based on Cd-free QDs and lanthanide ion-doped nanoparticles (e.g. tungstate based on previous work and fluoride). For vivo applications the nanocrystals may be coated with a silica shell and covered with a layer of lipid molecules to make them biocompatible. By precisely control the composition of compound, it is possible to realize multimodal bio-imaging (like probes for MRI). Furthermore, microscopes like STM will be used to detect the surface information of nanocrystal. 

    In addition to the promising probes for one-photon fluorescence imaging, the presently proposed probes will also be developed to serve as probes for two-photon excitation (TPE). This technique has the potential to be superior over one-photon excitation for the detection of macromolecules in living cells (longer observation times, better 3D spatial resolution, deeper tissue penetration depth and higher signal-to-background ratio). For the QDs the cross-section of TPE will be studied as a function of size and excitation wavelength, related to the (size-dependent) energy level structure of QDs. For the lanthanide ion doped nanocrystals TPE involves an upconversion process through energy transfer processes between lanthanide ions. Their performance will be evaluated and compared with existing (fluorescent dye) labels for two-photon imaging. Important parameters are conversion efficiency IR-to-Visible, action cross-section, power dependence, stability and biocompatibility. The ultimate goal of this project is to provide a technology that allows ultra-sensitive detection in biomedical research as well as in medical diagnostics using one- and two-photon imaging techniques.

Gegenereerd op 2017-06-23 14:15:37
Full name
Z. Wang MSc Contact details
Leonard S. Ornsteinlaboratorium

Princetonplein 1
Room -119
3584 CC  UTRECHT
The Netherlands


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Gegenereerd op 2017-06-23 14:15:37
Last updated 22.12.2016