Fluorescence modification, meaning either fluorescence enhancement or fluorescence diminishment, is obtained in a transparent layer structure comprised of a substrate, a dielectric layer and a fluorophore-labeled biomolecule layer. A metal particle layer is positioned in the layer structure a distance of 200-500 nm from the fluorophore-labeled biomolecule layer. Separation distances between 200 and 500 nanometers can be used to enhance or diminish fluorescence. All of the layers may be made transparent so that microscopic viewing of the fluorescence is possible from either side of the layer structure.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 The United States Government has rights in this invention pursuant to Contract No. DE-AC05-00OR22725 between the United States Department of Energy and UT-Battelle, LLC.