A Kretschmann-Raether prism-based three-layer structure consisting of a prism, gold (Au) metal film, and dielectric sample has been investigated with the use of admittance loci method in attenuated total internal reflection mode. High index prism materials like silicon, chalcogenide (2S2G), and SF14 have been used to study their effect on surface plasmon resonance (SPR) sensing (at 1200-nm wavelength) in infrared region by corresponding admittance loci plots and also by SPR sensing curves. The performance of the sensor based on the choice of the prism material has been discussed with the help of sensitivity plots giving due importance to the dynamic range of the designed sensor. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE) © 2013 SPIE.