Highly Sensitive Detection of Processes Occurring Inside Nanoporous Anodic Alumina Templates a Waveguide Optical Study
Abstract
Porous anodic alumina films have attracted great attention in the areas of nanoscience and engineering due to their well-ordered, densely packed, nanoscale pores that run straight through the film thickness. We apply these films as planar optical waveguides and, by monitoring the effective dielectric constants of the porous alumina layer, we achieve highly sensitive detection of conformal deposition on pore surfaces. Formation of molecular layers through silane coupling onto the alumina pore surfaces may be tracked, and sensing of specific adsorption of streptavidin onto biotinylated surfaces will be described. Non-specific adsorption, for example, of bovine serum albumin, can also be monitored with sub-angstrom sensitivity in effective thickness of layer deposited. Very high sensitivity is possible due to the presence of a large internal surface sensitive to external stimuli and to the precise conditions necessary for guiding confined optical modes. Apart from being a sensor of surface reactions and processes, the porous anodic alumina waveguide may also be used to monitor template deposition of a variety of materials in situ.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MAR.Z8009L