Biochips of corrugated gold and silver displaying surface plasmon resonance at different energies are fabricated to determine the nature of the mechanism responsible for the surface-enhanced chemiluminescence (SECL) of luminol. This Full Paper proves that, whereas silver possesses the strongest resonance and the greatest plasmon overlap with luminol emission, silver is also the metal that induces the lowest CL enhancement (two orders of magnitude less than gold). Therefore, the enhancement mechanism is not related to plasmon-assisted processes but rather originates from catalytic properties induced by corrugation of the metal film.