` Sensitive surface plasmon resonance biosensor enhanced by photonic-crystal metallic structure

In this paper, we propose and analytically demonstrate a novel photonic crystal metallic structure, where a photonic crystal (PC) structure is integrated in a total-internal-reflection (TIR) geometry. This unique configuration introduces a new plasmon excitation mechanism, and the excited plasmon modes satisfy the conditions for both resonance modes in PC structure and Plasmon modes in the metallic structure, which makes it possesses a narrow resonance width, smaller minimum reflectance and higher sensitivity comparing with the conventional SPR sensor. The novel and sensitive PC-metallic biosensor will serve as a promising choose for optical biosensing, and in enhanced total-internal-reflection fluorescence microscopy (TIRFM).