1. E-MRS Spring Meeting 2013, Strasbourg, France
Bright and Stable Nanoparticles: Synthesis and Bioimaging Applications
Tangi Aubert, Marco Cirillo, Amelie Biermann, Holger Lange, Stefaan Soenen, Kevin Braeckmans, Rik Van Deun, Edouard Brainis, Zeger Hens
E-MRS Spring Meeting 2013, Strasbourg, France

2. Functional silica NPs for biotechnologies
- Biocompatible
- High colloidal stability
- Versatile surface chemistry
- …
luminescent
magnetic
plasmonic
Burns A.A., Wiesner U. et al., Nano. Lett. 2009, 9 (1), 442
Lu C.H. et al., Nano. Lett. 2007, 7 (1), 150
Sokolov K. et al., Cancer Res. 2003, 63, 1999

3. Outline ● ‘Flash’ CdSe/CdS core-shell quantum dots
- synthesis, properties, low blinking
● nanoparticles
- synthesis, bright and stable
● Potential for bioimaging applications
- toxicity, cell uptake and labeling

4. ‘Flash’ CdSe/CdS QDs synthesis
● SILAR CdSe/CdS synthesis (successive ion layer adsorption and reaction)
→ highly time consuming Li et al., J. Am. Chem. Soc. 2003, 125, 12567
● FLASH CdSe/CdS synthesis: adapted from synthesis of CdSe/CdS
dot-in-rods Carbone et al., Nano Lett. 2007, 7 (10), 2942
T = 330°C
CdO
oleic acid
TOPO N2
CdSe
+ TOP-S
3 min reaction !!
T. Aubert et al., in preparation

5. ‘Flash’ CdSe/CdS QDs synthesis
Morphology, size control and optical properties
sharp emission
high quantum yield (40%)
Ø = 6.6 nm
tunable CdS thickness
→ up to 6 nm thick CdS shell in no more than 3 minutes
T. Aubert et al., in preparation

6. ‘Flash’ CdSe/CdS QDs synthesis
Raman analysis
→ low blinking
→ interfacial alloying
T. Aubert et al., in preparation

7. CdSe/CdS@SiO2 nanoparticles
Synthesis by water-in-oil microemulsion
inverted micelle
hydrolyzed TEOS
amphiphilic ligand
hydrophobic NP

8. CdSe/CdS@SiO2 nanoparticles
Morphology and optical properties
high stability of the luminescence in water
T. Aubert et al., in preparation

9. CdSe/CdS@SiO2 for bioimaging
Toxicity tests on human umbilical vein endothelial cells (HUVECs)
24 hrs exposition
*: p < 0.05
**: p < 0.01
→ low toxicity (first significant effect at [NPs] = 100 nM)
T. Aubert et al., in preparation

10. CdSe/CdS@SiO2 for bioimaging
HUVECs cell labeling ([NPs] = 50 nM, 24 hrs)
red channel (NPs)
green channel (dye)
merged (NPs + dye)
40 µm
→ rapid endosomal uptake of high levels of NPs
T. Aubert et al., in preparation

11. CdSe/CdS@SiO2 for bioimaging
Long term cell visualization (HUVECS, [NPs] = 50 nM, 24 hrs)
0 cell division
3 cell divisions
7 cell divisions
40 µm
→ up to 9 cell division can be observed
T. Aubert et al., in preparation

12. Conclusion tangi.aubert@ugent.be ● ‘Flash’ CdSe/CdS synthesis
- fast and tunable
● nanoparticles
- good morphology
- high stability in water
● High potential for bioimaging
- low toxicity
- fast and high uptake
- long term labeling

13. Thanks for your attention !
Aknowledgement
Max Kade
Foundation
Thanks for your attention !