In this research, a flower shape photonic crystal fiber sensor is proposed and designed. In this sensor, the most electromagnetic field is concentrated in the core part of the flower that causes a surprising increase in the sensitivity of the sensor. Gold is used as a plasmonic material for stability in the environment. The analyte is placed outside the sensor and it makes the possibility of fabrication simple. The geometrical parameters of the sensor are optimized with the Nelder Mead algorithm. The detection power of the sensor is in the bio range and in this research it is proposed to determine the concentration of sucrose and the concentration of hemoglobin. The results show an excellent amplitude sensitivity of 5285 (RIU-1) and a suitable wavelength sensitivity of 11000 (nm/RIU).