Boosting the Sensitivity of Cu-based SPR Dengue Sensor Using Cu/Compound Semiconductor/BaTiO3 Configuration for Effective Early-Stage Dengue Detection

A sizable 430°/RIU (refractive index unit) sensitivity for the dengue detection is reported using the surface plasmon resonance (SPR) technique with the copper/compound semiconductor/BaTiO₃ configuration. The involvement of the copper makes the device significantly less expensive than the conventional gold (Au)/silver (Ag)-based SPR sensors and that can significantly lower the diagnostic cost. The study uses healthy and sickened plasma, platelets, and haemoglobin using blood as a biosample and shows the highest sensitivity for plasma, which notably contains the highest non-structural protein (NS1) in the early stage. The combined effect of compound semiconductor nitrides (aluminium nitrite (AlN), silicon nitrite (Si₃N₄), or gallium nitrite (GaN)) and BaTiO₃ helps to boost the sensor’s sensitivity and selectivity together. The angular sensitivity of 430°/RIU and quality factor (QF) of 136 RIU⁻¹ is achieved using Cu (58 nm), AlN (14 nm), and BaTiO₃ (1 nm). The aforesaid advantages along with a visible operating wavelength of λ = 633 nm make the proposed device a considerable design achievement for development of low-cost sensing equipment for efficient dengue detection.