Influence of the nanoscale structure of gold thin films upon peroxidase-induced chemiluminescence
Résumé
Goldthin films with different nanoscaled roughness were elaborated by a pulsed-laser deposition technique in order to evaluate their ability to form biochip substrates. The crystal structure, microstructure, and optical absorption were investigated by x-ray diffraction, atomic force microscopy, and ultraviolet-visible absorption spectrum. Controlling the temperature of the substrate during the deposition process allows us to obtain samples with different roughness and grain sizes. The temperature can then be adjusted to elaborate thin films, which have either the optical behavior of bulk metal or that of individual clusters. This optical behavior strongly influences the chemiluminescence at 425nm of luminol brought to the vicinity of peroxidase supported by biomolecules physi- or chemisorbed on the films. In particular, the signal intensity increases of almost one order of magnitude when the film presents a significant surface resonance plasmon.