▎ 摘　　要

A novel eccentric photonic crystal fiber biosensor with gold and graphene bimetallic layers on the outer edge of the optical fiber is proposed in this paper. The effects of gold film thickness, graphene coating thickness and cladding air hole diameter on the sensor performance are analyzed in detail. The maximum sensitivity of this PCF sensor is 4657.14 nm/RIU when only gold-plated film is used, and 8600 nm/RIU after a layer of graphene is added on the gold film, the sensitivity increased by 84.66%. Compared with the traditional optical fiber sensor, this PCF sensor has the advantages of simple structure, easy manufacture and real-time detection, which will make it a potential candidate for water quality analysis, chemical detection and biomolecular detection.