Design considerations of photonic crystal fiber (PCF) surface plasmon biosensor with high sensitivity to monitor glucose concentration is reported and studied. Based on a well-known large mode area (LMA) single mode PCF, two different configurations have been studied to investigate the impact of the etching process on the biosensor sensitivity. Furthermore, the possibility of infiltrating one hole by a plasmonic material to increases the biosensor sensitivity is studied. A full vectorial finite element method (FVFEM) is used to carry out the analysis of the reported biosensor. In addition, the geometrical parameters of the suggested biosensors have been optimized to obtain the highest sensitivity. The suggested biosensor based on a D-shaped PCF with plasmonic rod achieves sensitivity as high as 13,600 nm/RIU with corresponding resolution of 7.35×10-6RIU.The analysis also reveals that the proposed biosensor has a linear performance which is needed practically. Therefore, the reported biosensor has advantages in terms of fabrication feasibility and high linear sensitivity
