Synthesis and properties of water-soluble CdSe/Zn1-xMn xS semiconductor quantum dots using an amphiphilic polymer

Shizhong Wang, Angelique Y. Louie, Susan M. Kauzlarich

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We report the phase transfer of hydrophobic CdSe/Zn1-xMn xS quantum dots (QDs) into water by encapsulation with octylamine-modified poly(acrylic acid) (PAA). CdSe/Zn1-xMn xS QDs are of interest as multimodality biological probes where the photoluminescence and magnetic relaxivity can be tuned independently. Different percentages of the carboxyl groups in PAA were grafted with octylamine molecules and the modified PAA was used for capping CdSe/Zn1-xMnxS QDs to make them water soluble. We investigated the optical properties and the solubility of the CdSe/Zn1-xMnxS QDs in water. It was found that the PAA with a modification percentage of ∼45% resulted in soluble CdSe/Zn1-xMnxS QDs with the highest quantum yield (QY) in water of approximately 20%. The QY of CdSe/Zn1-xMn xS QDs in water was lower than the initial measurement in chloroform and dropped in the initial stages of phase transfer, stabilizing at 20%. Hydrodynamic size of the polymer encapsulated CdSe/Zn1-xMn xS QDs in water was evaluated by dynamic light scattering (DLS). The smallest average hydrodynamic diameter of ∼30 nm was achieved when the molecular ratio of QDs to PAA for capping was 1 nanomole of QDs to 24 micromole of monomer unit.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume6448
DOIs
StatePublished - 2007
EventColloidal Quantum Dots for Biomedical Applications II - San Jose, CA, United States
Duration: Jan 20 2007Jan 23 2007

Other

OtherColloidal Quantum Dots for Biomedical Applications II
CountryUnited States
CitySan Jose, CA
Period1/20/071/23/07

Keywords

  • Nanoparticles
  • Optical properties
  • Particle size
  • Quantum dots
  • Semiconductor
  • Water-soluble

ASJC Scopus subject areas

  • Engineering(all)

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    Wang, S., Louie, A. Y., & Kauzlarich, S. M. (2007). Synthesis and properties of water-soluble CdSe/Zn1-xMn xS semiconductor quantum dots using an amphiphilic polymer. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE (Vol. 6448). [64480A] https://doi.org/10.1117/12.701447