In this study, a plasmonic photonic crystal fiber (PCF) sensor was designed with an internal gold layer between the liquid holes and the air holes. The study shown that the thickness of the gold layer, the radius of the air holes and the radius of the liquid holes all have a significant effect on the sensitivity of the sensor, where a wavelength sensitivity of (10,500 nm/RIU) was achieved at certain simulation conditions. Under these chosen conditions, the relationship of resonance wavelength with the refractive index of the liquid was linear and this gives flexibility to extend the range of the refractive index of the analyte without changing the sensor design. Approaching or moving away of the holes from center in the proposed design has a fundamental role in determining the sensor characteristics
