E-MRS Spring Meeting 2013, Strasbourg, France Bright and Stable CdSe/CdS@SiO2 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

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

Outline ● ‘Flash’ CdSe/CdS core-shell quantum dots - synthesis, properties, low blinking ● CdSe/CdS@SiO2 nanoparticles - synthesis, bright and stable ● Potential for bioimaging applications - toxicity, cell uptake and labeling

‘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

‘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

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

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

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

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

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

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

Conclusion tangi.aubert@ugent.be ● ‘Flash’ CdSe/CdS synthesis - fast and tunable ● CdSe/CdS@SiO2 nanoparticles - good morphology - high stability in water ● High potential for bioimaging - low toxicity - fast and high uptake - long term labeling

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