Numerical Investigation on High-Performance Cu-Based Surface Plasmon Resonance Sensor for Biosensing Application

This numerical research presents a simple hybrid structure comprised of TiO2-Cu-BaTiO3 for a modified Kretschmann configuration that exhibits high sensitivity and high resolution for biosensing applications through an angular interrogation method. Recently, copper (Cu) emerged as an exceptional choice as a plasmonic metal for developing surface plasmon sensors (SPR) with high resolution as it yields finer, thinner SPR curves than Ag and Au. As copper is prone to oxidation, especially in ambient conditions, the proposed structure involves the utilization of barium titanate (BaTiO3) film as a protection layer that not only preserves Cu film from oxidizing but enhances the performance of the sensor to a great extent. Numerical results also show that the utilization of a thin adhesive layer of titanium dioxide (TiO2) between the prism base and Cu film not only induces strong interaction between them but also enhances the performance of the sensor. Such a configuration, upon suitable optimization of the thickness of each layer, is found to enhance sensitivity as high as 552 & DEG;/RIU with a figure of merit (FOM) of 136.97 RIU-1. This suggested biosensor design with enhanced sensitivity is expected to enable long-term detection with greater accuracy and sensitivity even when using Cu as a plasmonic metal.

Automated summary

This study presents a simple hybrid structure of TiO2-Cu-BaTiO3 that demonstrates high sensitivity and resolution for biosensing applications using an angular interrogation method. Copper (Cu) has been identified as an excellent choice for surface plasmon sensors (SPR) due to its ability to produce finer SPR curves compared to Ag and Au. To overcome copper oxidation, a protective layer of barium titanate (BaTiO3) is incorporated, which not only prevents oxidation but also enhances sensor performance. The addition of a thin adhesive layer of titanium dioxide (TiO2) between the prism base and Cu film further improves sensor performance. Upon optimization, this configuration achieves a sensitivity as high as 552 RIU with a figure of merit (FOM) of 136.97 RIU-1, making it an ideal biosensor design for long-term detection with enhanced accuracy and sensitivity, even using Cu as a plasmonic metal.