Journal of Sol-Gel Science and Technology

, Volume 46, Issue 3, pp 313–322

Light-activated functional mesostructured silica

  • Erik Johansson
  • Eunshil Choi
  • Sarah Angelos
  • Monty Liong
  • Jeffrey I. Zink
Original Paper

DOI: 10.1007/s10971-007-1661-4

Cite this article as:
Johansson, E., Choi, E., Angelos, S. et al. J Sol-Gel Sci Technol (2008) 46: 313. doi:10.1007/s10971-007-1661-4
  • 225 Downloads

Abstract

Mesostructured silica thin films and particles provide highly versatile supports or frameworks for functional materials where a desired function (such as energy transfer, electron transfer, or molecular machines) is induced by molecules deliberately placed in specific regions of the structure. The relatively gentle templated sol–gel synthesis methods allow a wide variety of molecules to be used, and the optical transparency of the framework is very suitable for studies of light-induced functionality. In this paper, three types of functionality are used to obtain fundamental understanding of the materials themselves and to develop active materials that can trap and release molecules from the pores upon command. Photo-induced energy transfer is used to verify that molecules can be placed in specific spatially separated regions of the framework; fluorescence resonance energy transfer is used as a molecular ruler to measure quantitatively the distance between pairs of molecules. Secondly, photo-induced electron transfer is used to obtain fundamental information about the electrical insulating properties of the framework. Finally, two types of molecular machines, a light-driven impeller and a light activated nanovalve, are described. Both machines contain moving parts attached to solid supports and do useful work. The valves trap and release molecules from the mesopores, and the impellers expel molecules from the pores. Applications of the materials to drug delivery and the release of drug molecules inside living cells is described.

Keywords

Energy transfer Electron transfer Nano machines Nano valves 

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Erik Johansson
    • 1
  • Eunshil Choi
    • 1
  • Sarah Angelos
    • 1
  • Monty Liong
    • 1
  • Jeffrey I. Zink
    • 1
  1. 1.Department of Chemistry and BiochemistryUniversity of California at Los AngelesLos AngelesUSA

Personalised recommendations