SODIUM CHLORIDE CONCENTRATION SENSOR BASED ON ENHANCED SURFACE PLASMON RESONANCE BY A TiO_2-ZnO COMPOSITE FILM AND AN Au NANOWIRE ARRAY USING A MoS_2-GRAPHENE-OXIDE HYBRID NANOSHEET

摘要

We propose a method for low-concentration detection of sodium chloride based on surface plasmon resonance (SPR). A novel prism coupling structure is designed for the sodium chloride concentration sensor, where a TiO2-ZnO composite film and a MoS2-GO hybrid nanosheet are chosen to enhance the surface plasmon resonance based on an Au nanowire array because of their unique properties in metal nanowire arrays and two-dimensional nanomaterials. Using the finite element method, we analyze the thickness of each medium layer for the structure designed in order to obtain the optimum value, so that the sensitivity of the sodium chloride concentration sensor designed is substantially enhanced. The optimum thickness of each medium layer is given, and the sensitivity of the sodium chloride concentration sensor based on the surface plasmon resonance can reach 0.260 degrees/ (g/100 ml) concentration in the detection range of the sodium chloride concentration from zero to 15 g/100 ml. We derive the relationship between the sodium chloride concentration and the surface plasmon resonance angle in the detection range of the sodium chloride concentration.