Multilayer models for single mode optical fiber based on Long Range Surface Plasmon Resonance (LRSPR) coated with silver (Ag) and gold (Au) with dielectric function of MgF2 are introduced. Properties for the models are theoretically and experimentally reported in this work. Firstly, the performances of different models are investigated using COMSOL simulation. Different combinations of magnesium fluoride (MgF2) and Ag/Au material embedded layers are applied to observed functionality of dielectric layers underneath the analyte. In theoretical analysis, MgF2-Ag and MgF2Ag-MgF2 layers conveys the best performance in sensing. The combination of plasmonic material Ag with MgF2 rather than Au shows higher sensitivity response. The experimental has been carried out with these configurations where exhibit the sensitivities of 1762.5 nm/RIU and 1250 nm/RIU at 1.371.38 and 1.33-1.34 RI range respectively for silver-based models. The outcomes indicate the proposed LRSPR based models with specific dielectric where here MgF2 found to be a strong match in sensing applications.