This thesis will characterize the use of HFAPNB and PHOST as a sensing layer material for a fully integrated multi-mode interferometric evanescent waveguide. The compatibility of HFAPNB and PHOST with standard CMOS and MEMS processing allowed us to explore their characteristics for sensing different analytes which included water, methanol, isopropyl alcohol, and benzene. The relative sensitivity of the polymer HFAPNB and PHOST to different chemicals has been quantified and related to a refractive index shift and thickness change of the polymers. Diffusion coefficients have also been quantified for both polymers and interaction models for each polymer and analyte has been determined to predict the concentration of a mixture of analytes.