Enhancing the sensitivity of surface plasmon resonance (SPR) sensors is critical for detecting lower analyte concentrations and smaller biomolecular interactions. In this study, we designed and developed a surface plasmon resonance (SPR) sensor platform based on hyperbolic metamaterials (HMMs). The sensor is composed of Ag/Al2O3 multilayer composites, and a genetic algorithm (GA) was employed to systematically determine the optimal parameter configuration for the HMMs-based SPR sensor. Furthermore, theoretical analysis was conducted using the finite element analysis method, revealing that the electric field intensity within the hyperbolic metamaterial exhibits a layer-by-layer increasing trend, with significant field enhancement predominantly occurring within the dielectric layers. Compared with conventional SPR sensors, where electric field enhancement is confined to a single interface, the HMMs structure demonstrates a clear advantage in field enhancement, thereby substantially improving the sensitivity of the SPR sensor. Experimental results further validated the performance of the sensor, achieving a refractive index (RI) sensitivity of 43.62 μm/RIU, which represents an improvement of approximately 1 order of magnitude compared with traditional SPR sensors. This platform was used to test for the Alzheimer's disease biomarker β-amyloid 1-42 (Aβ1-42), achieving an ultralow limit of detection (LOD) of 0.18 pg/mL. GA design provides a generalized approach to improving device performance and is expected to have a significant impact on the design and application of sensors.
Zhao et al. (Wed,) studied this question.