Optimizing HfO2-supported surface plasmon resonance biosensor sensitivity through MXene integration

Surface plasmon resonance (SPR) sensors are fundamental in biomolecular detection, yet they face limitations due to the restricted sensitivity of traditional gold (Au) and silver (Ag) films. This research introduces an innovative SPR biosensor design that incorporates a hafnium dioxide (HfO₂) layer combined with MXene nanosheets to significantly boost performance. We conduct a numerical analysis of the sensor design using the transfer matrix method (TMM) to evaluate its resonance properties and overall effectiveness. The addition of an MXene layer is found to greatly enhance the resonance angle shift. The optimized sensor exhibits outstanding performance metrics, achieving a sensitivity of 257°/RIU, a figure of merit (FoM) of 38.30 RIU^-1, and a detection limit (LOD) of 3.89 × 10^-6, which significantly exceeds those of conventional Au/Ag-based sensors. These findings confirm that the HfO₂ - MXene composite nanostructure is a highly promising platform for the sensitive detection of low-concentration analytes, offering substantial potential for advancing biomedical diagnostics and next-generation sensing applications.