<p>Reliable and quick coronavirus detection is still necessary for the efficient disease monitoring and public safety. This work proposes an extremely sensitive sensor based on surface plasmon resonance (SPR) technique for SARS-CoV-2 detection using an NSG prism/silver (Ag)/gallium nitride (GaN)/barium titanate (BaTiO₃) multilayered structure. The addition of GaN as a large band gap material improve the sensing performance which further increases the interaction with the sensing medium of the evanescent field. The transfer matrix approach (TMA) is used to examine the sensing mechanism with the 633&#xa0;nm wavelength. Further, the Taguchi optimization approach is used to identify the ideal thicknesses of the Ag, GaN, and BaTiO₃ layers in order to further enhance sensor functionality. In this, the impact of layers thickness variation on important performance metrics, including as full width at half maximum (FWHM) is thoroughly assessed using an L9 Taguchi array. The most important design factors influencing sensor response are found using analysis of variance (ANOVA) method and Taguchi signal-to-noise ratio (SNR) assessment. Here, the Taguchi SNR is utilized as a statistical optimization indicator to determine the optimal design parameters for minimizing the FWHM based on the ‘smaller is better’ criterion. Higher resonance angle shifting and better sensing performances are observed by this optimized sensor design. Further, the findings show that the combination of this optimization with GaN integration offers a potential foundation for the creation of highly effective SPR sensor structure for SARS-CoV-19 detection. Hence, this suggested method provides insightful information for the development of novel plasmonic sensors for monitoring pathogens and clinical diagnosis.</p>