Design of a highly sensitive plasmonic sensor based on platinum diselenide/blue phosphorene–tungsten disulfide/graphene oxide/aluminium oxide heterostructure for the detection of uric acid concentration

Abstract Conventional biosensors often suffer from reduced long-term performance because they rely on bio-recognition elements, such as enzymes and antibodies, which degrade over time. This study proposes a label-free heterostructured surface plasmon resonance-based sensor for highly sensitive detection of uric acid (UA) at different concentrations. The proposed design incorporates platinum diselenide (PtSe2)/blue phosphorene–tungsten disulfide (BlueP-WS2)/graphene oxide (GO)/aluminium oxide (Al2O3) architecture to enhance the optical coupling and sensing performance. The finite-difference time-domain method is used for optimizing and analysing the sensor's performance. The optimized structure achieved a maximum sensitivity of 401 deg RIU–1, a quality factor (QF) of 72.1597 RIU⁻¹ at UA concentrations of 100 and 200 ppm, and a detection accuracy (DA) of 0.028864 at 500 ppm. The sensor also demonstrated a low limit of detection (LOD) of 2.4938 × 10⁻⁶ RIU, emphasizing its high detection precision. The synergistic effect of the incorporated materials, such as Al2O3, PtSe2, BlueP-WS2, and GO, significantly improved the overall sensor performance by increasing sensitivity and DA. Overall, the results demonstrate that the proposed hybrid sensor provides a reliable, highly sensitive, and reproducible platform for UA detection, with promising potential for non-invasive and label-free biomedical diagnostics.