Water-soluble pegylated quantum dots: from a composite hexagonal phase to isolated micelles

Langmuir. 2006 Nov 7;22(23):9797-803. doi: 10.1021/la061849h.

Abstract

We present a simple method based on the dispersion of fluorescent quantum dots (QD) into a liquid crystal phase that provides either nanostructured material or isolated QD micelles depending on water concentration. The liquid-crystal phase was obtained by using a gallate amphiphile with a poly(ethylene glycol) chain as the polar headgroup, named I. The hydration of QD/I mixtures resulted in the formation of a composite hexagonal phase identified by small-angle X-ray scattering and by polarized light and fluorescence optical microscopy, showing a homogeneous distribution of fluorescence within hexagonal phase. This composite mesophase can be converted into isolated QD-I micelles by dilution in water. The fluorescent QD-I micelles, purified by size exclusion chromatography, are well monodisperse with a hydrodynamic diameter of 20-30 nm. Moreover, these QD do not show any nonspecific adsorption on lipid or cell membranes. By simply adjusting the water content, the PEG gallate amphiphile I provides a simple method to prepare a self-organized composite phase or pegylated water soluble QD micelles for biological applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electrons
  • Lipids / chemistry
  • Micelles*
  • Microscopy, Electron, Transmission
  • Molecular Structure
  • Polyethylene Glycols / chemistry*
  • Quantum Dots*
  • Solubility
  • Spectrum Analysis
  • Water / chemistry*

Substances

  • Lipids
  • Micelles
  • Water
  • Polyethylene Glycols