In this paper, indium tin oxide (ITO) is considered as an alternative plasmonic material beyond conventional plasmon generating metal. A total of 150-nm-thick ITO film-based Kretschmann configuration is demonstrated in NIR region. Minimum possible reflectance with optimum FWHM of resonance plot is the essential criteria for the incident angle selection of the said structure to increase the sensitivity and improve the performance of SPR biosensors in wavelength interrogation mode. Reflectance, phase, and field enhancement curves have been studied for different gaseous samples, and corresponding wavelength sensitivity has been calculated for the change of refractive index of the sample in the order of two. Differential resonance parameters have also been studied which are found to provide increased sensitivity. Theoretical simulation-based results validate that the proposed sensor can provide higher sensitivity by measuring the differential phase.

在本文中，氧化铟锡（ITO）被认为是替代常规等离子体产生金属的等离子体材料。在NIR区域展示了总共150 nm厚的基于ITO膜的Kretschmann配置。具有最佳共振频率FWHM的最小可能反射率是选择所述结构的入射角以提高灵敏度和改善SPR生物传感器在波长询问模式下的性能的基本标准。研究了不同气态样品的反射率，相位和场增强曲线，并为样品的折射率变化计算了相应的波长灵敏度，其变化幅度约为2。还研究了差分共振参数，发现它们提供了更高的灵敏度。