This article investigates a photonic crystal fiber(PCF) based surface plasmon resonance biosensor for the detection of the presence of E-coli bacteria in water. The presented sensing device is based on PCF designed with a hybrid lattice comprising one circular ring as the innermost one and two hexagonal rings surrounding it. A full-vectorial finite element method is used for modal analysis of the PCF design. The phase-matching condition occurs at 0.693µm,1.332µm, 1.78µm. The maximum wavelength sensitivity of 3472 nm/RIU, when the range of refractive index (RI)is from 1.401 to 1.585 and 2434 nm/RIU when the range of refractive index (RI) is from 1.585 to 1.769. The maximum amplitude sensitivity for our sensor is observed at -474.4629 RIU, and -474.4629737 RIU at 0.63µm and 1.777 µm respectively.