Photon gated transport at the glass nanopore electrode

J Am Chem Soc. 2006 Oct 18;128(41):13553-8. doi: 10.1021/ja064274j.

Abstract

The interior surface of the glass nanopore electrode was modified with spiropyran moieties to impart photochemical control of molecular transport through the pore orifice (15-90 nm radius). In low ionic strength acetonitrile solutions, diffusion of a positively charged species (Fe(bpy)(3)(2+)) is electrostatically blocked with approximately 100% efficiency by UV light-induced conversion of the neutral surface-bound spiropyran to its protonated merocyanine form (MEH+). Transport through the pore orifice is restored by either irradiation of the electrode with visible light to convert MEH+ back to spiropyran or addition of a sufficient quantity of supporting electrolyte to screen the electrostatic field associated with MEH+. The transport of neutral redox species through spiropyran-modified glass nanopores is not affected by light, allowing photoselective transport of redox molecules to the electrode surface based on charge discrimination. The glass nanopore electrode can also be employed as a photochemical trap, by UV light conversion of surface-bound spiropyran to MEH+, preventing Fe(bpy)(3)(2+) initially in the pore from diffusing through the orifice.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2,2'-Dipyridyl / analogs & derivatives
  • Acetonitriles / chemistry
  • Benzopyrans / chemistry*
  • Chelating Agents / chemistry*
  • Diffusion
  • Electrochemistry
  • Electrodes
  • Glass / chemistry*
  • Indoles / chemistry*
  • Iron / chemistry
  • Nanostructures / chemistry*
  • Nitro Compounds / chemistry*
  • Organometallic Compounds / chemistry*
  • Osmolar Concentration
  • Photochemistry
  • Photons*
  • Porosity
  • Static Electricity
  • Surface Properties
  • Ultraviolet Rays

Substances

  • Acetonitriles
  • Benzopyrans
  • Chelating Agents
  • Indoles
  • Nitro Compounds
  • Organometallic Compounds
  • spiropyran
  • 2,2'-Dipyridyl
  • Iron
  • acetonitrile