In this paper, a highly sensible photonic crystal fiber based on a modified hexagonal structure has mentioned and demonstrated modal analysis precisely. Numerical investigation of the proposed fiber is rigorously computed using full vector finite element method (FV-FEM) with anisotropic perfect match layers. Liquid analytes are used here to infiltrate fiber core. Relative sensitivity is numerically investigated and optimized by varying the different parameters of the proposed structure at a wider wavelength regime 1.0–1.7 μm within IR region. The proposed simple structural PCF shows higher sensitivity as a chemical sensor for lower refractive index chemicals such as Water, Ethanol and Benzene. Moreover, some essential properties such as confinement loss, V parameter, spot size, beam divergence, and nonlinearity are also represented distinctly. The proposed PCF gains higher sensitivity of 53.22%, 48.19% and 55.56% for Ethanol, Water and Benzene respectively at 1.33 μm wavelength with lower confinement loss. Above result reveals that proposed fiber is capable to provide potential impact in telecommunications, chemical sensing as well as bio-sensing also.