How surface-enhanced chemiluminescence depends on the distance from a corrugated metal film

Peroxidase labeled streptavidin was immobilized onto the surface of bulk and clusterlike metal films at a distance controlled by a peptide chain with a length between 1.3 and 7.8 nm. Luminol chemiluminescence which occurred at peroxidase vicinity depends on the metal nanostructure. When peroxidase is attached on a bulklike film, chemiluminescence increases monotonously with the distance because of a decrease of the light emission quenching by metal. When peroxidase is attached on a clusterlike film, chemiluminescence undergoes a complex variation with the metal/catalyst distance evidencing a competition between the already mentioned quenching process and a nanostructure-induced catalysis enhancement. (c) 2006 American Institute of Physics.