Surface plasmon coupled chemiluminescence from iron thin films: Directional and approaching fixed angle observation

We report the observation of surface plasmon coupled chemiluminescence (SPCC) from iron thin films. Theoretical Fresnel calculations were employed to determine the optimum thickness of iron thin films to be 15 nm, which is assessed by the value of minimum reflectivity curves for incident light upon the thin film. An overlayer 10 nm thick SiO ₂ was used to protect the iron thin films from oxidation by air or physical changes induced by chemiluminescent solutions. SPCC emission from blue, green, and chartreuse chemiluminescent solutions on iron films can be observed at a fixed angle of 60° for all the chemiluminescent solutions, while free-space emission was isotropic. Iron thin films do not have a catalytic effect on chemiluminescence emission.