Micelle-templated composite quantum dots for super-resolution imaging

Nanotechnology. 2014 May 16;25(19):195601. doi: 10.1088/0957-4484/25/19/195601. Epub 2014 Apr 24.

Abstract

Quantum dots (QDs) have tremendous potential for biomedical imaging, including super-resolution techniques that permit imaging below the diffraction limit. However, most QDs are produced via organic methods, and hence require surface treatment to render them water-soluble for biological applications. Previously, we reported a micelle-templating method that yields nanocomposites containing multiple core/shell ZnS-CdSe QDs within the same nanocarrier, increasing overall particle brightness and virtually eliminating QD blinking. Here, this technique is extended to the encapsulation of Mn-doped ZnSe QDs (Mn-ZnSe QDs), which have potential applications in super-resolution imaging as a result of the introduction of Mn(2+) dopant energy levels. The size, shape and fluorescence characteristics of these doped QD-micelles were compared to those of micelles created using core/shell ZnS-CdSe QDs (ZnS-CdSe QD-micelles). Additionally, the stability of both types of particles to photo-oxidation was investigated. Compared to commercial QDs, micelle-templated QDs demonstrated superior fluorescence intensity, higher signal-to-noise ratios, and greater stability against photo-oxidization,while reducing blinking. Additionally, the fluorescence of doped QD-micelles could be modulated from a bright 'on' state to a dark 'off' state, with a modulation depth of up to 76%, suggesting the potential of doped QD-micelles for applications in super-resolution imaging.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Fluorescence
  • Manganese Compounds / chemistry
  • Micelles*
  • Microscopy, Fluorescence*
  • Nanocomposites / chemistry*
  • Quantum Dots / chemistry*
  • Selenium Compounds / chemistry
  • Signal-To-Noise Ratio
  • Zinc Compounds / chemistry

Substances

  • Manganese Compounds
  • Micelles
  • Selenium Compounds
  • Zinc Compounds