Fluorescent single walled carbon nanotube/silica composite materials

ACS Nano. 2008 Nov 25;2(11):2283-90. doi: 10.1021/nn8003839.

Abstract

We present a new approach for the preparation of single walled carbon nanotube silica composite materials that retain the intrinsic fluorescence characteristics of the encapsulated nanotubes. Incorporation of isolated nanotubes into optically transparent matrices, such as sol-gel prepared silica, to take advantage of their near-infrared emission properties for applications like sensing has been a challenging task. In general, the alcohol solvents and acidic conditions required for typical sol-gel preparations disrupt the nanotube/surfactant assembly and cause the isolated nanotubes to aggregate leading to degradation of their fluorescence properties. To overcome these issues, we have used a sugar alcohol modified silica precursor molecule, diglycerylsilane, for encapsulation of nanotubes in silica under aqueous conditions and at neutral pH. The silica/nanotube composite materials have been prepared as monoliths, at least 5 mm thick, or as films (<1 mm) and were characterized using fluorescence and Raman spectroscopy. In the present work we have investigated the fluorescence characteristics of the silica encapsulated carbon nanotubes by means of redox doping studies as well as demonstrated their potential for biosensing applications. Such nanotube/silica composite systems may allow for new sensing and imaging applications that are not currently achievable.

Publication types

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

MeSH terms

  • Alcohols / chemistry
  • Biosensing Techniques
  • Crystallization
  • Electrochemistry / methods
  • Fluorescence*
  • Hydrogen-Ion Concentration
  • Materials Testing
  • Nanotechnology / methods
  • Nanotubes / chemistry
  • Nanotubes, Carbon / chemistry*
  • Optics and Photonics*
  • Oxidation-Reduction
  • Silicon Dioxide / chemistry*
  • Surface Properties
  • Surface-Active Agents

Substances

  • Alcohols
  • Nanotubes, Carbon
  • Surface-Active Agents
  • Silicon Dioxide