A high sensitivity gold coated circular nano-film photonic crystal fiber (PCF) biosensor based on surface plasmon resonance (SPR) is proposed. Finite element method (FEM) has been applied to simulate and analyze the sensing performance of the proposed circular structure. The highest sensitivity response and birefringence of 45003.05 nm/RIU and 1.9 × 10² are obtained respectively, where the operating refractive index (RI) analyte range is 1.33–1.40 and the gold layer thickness is 50 nm. It is the maximum sensitivity response where the RI analyte range is 1.33–1.40. Changing the gold layer thickness, the sensitivity response of 48269.50 nm/RIU is achieved for 70 nm gold layer where the operating gold layer thickness range is 40 nm to 90 nm. In short, the suggested circular SPR PCF structure can be broadly applicable in RI sensing applications for its outstanding sensitivity response, simple compact structure design and tunable performance.

提出了一种基于表面等离子体共振（SPR）的高灵敏度镀金圆形纳米薄膜光子晶体光纤（PCF）生物传感器。有限元方法（FEM）已被用于模拟和分析所提出的圆形结构的传感性能。最高灵敏度响应和双折射为45003.05 nm / RIU和1.9×10 ²分别获得，其中工作折射率（RI）分析物范围为1.33-1.40，金层厚度为50 nm。这是RI分析物范围为1.33–1.40时的最大灵敏度响应。改变金层的厚度，对于70 nm金层（其工作金层厚度范围为40 nm至90 nm），可获得48269.50 nm / RIU的灵敏度响应。简而言之，建议的圆形SPR PCF结构具有出色的灵敏度响应，简单的紧凑型结构设计和可调性能，因此可广泛应用于RI感测应用。