Recent advances in dielectric and two-dimensional material-based surface plasmon resonance biosensors for ultrasensitive refractive index sensing and diverse applications

Abstract

Advanced biosensors utilizing Surface Plasmon Resonance (SPR) are becoming powerful label-free optical sensing platforms for the real-time detection of biochemical interactions owing to their incredibly high sensitivity toward refractive index (RI) changes. Conventional metal-based SPR sensors typically suffer from optical losses, large resonance curves, and degraded detection sensitivity. The combination of widespread advances in high-RI dielectric materials and two-dimensional (2D) nanomaterials has greatly contributed to the improvement of SPR sensor performance, as a result of improved electromagnetic field confinement, enhanced biomolecular interactions, and higher overall sensing efficiency. This review summarizes the progress in dielectric- and 2D material-based SPR biosensors for both applications: ultrasensitive RI sensing and diverse biomedical, environmental, and chemical sensing. The basic concept of SPR, sensing performance indicators, and the nature of dielectric and 2D materials, multilayer devices, and theoretical modelling strategies are reviewed in detail. Moreover, the enhancement of RI sensing and biomarker detection is presented recently to analyze their benefits and obstacles experienced by different material platforms. Lastly, we gather the ongoing challenges in material stability, fabrication complexity, and clinical translation, along with the advent of new opportunities such as artificial intelligence-assisted sensor optimization, portable sensing systems, and next-generation hybrid plasmonic platforms. A holistic overview through this review will motivate researchers to develop cutting-edge SPR biosensors in the near future for advanced label-free detection applications.