Rapid and Highly Sensitive Detection of Sepsis Inflammatory Factors Based on a Plasmonic Terahertz-Metasurface Biosensor

Sepsis is a highly dynamic and intricate medical condition that has the potential to swiftly advance toward critical organ dysfunction and fatality. Timely identification and management of sepsis is of utmost importance, as it has the potential to significantly decrease mortality rates and enhance overall clinical results. However, current clinical detection techniques are difficult to fulfill someone's requirements due to the limitations of many factors, so a rapid and highly sensitive detection method is urgently needed. Here, we propose a plasma terahertz (THz) metasurface biosensor based on the principle of surface plasmon resonance, which allows strong coupling between electric and toroidal dipoles to produce extremely high local electric field enhancement that enhances light-matter interactions, resulting in intrinsic peaks with high-quality factor ( $Q)$ up to 19.36. To demonstrate its superior biosensing performance, we integrated antibody-functionalized metasurfaces in a 2-D microarray format for influx and real-time binding assay of inflammatory factors calcitoninogen procalcitonin (PCT), interleukin-10 (IL-10) solutions, with a detection limit of 100 ng/mL. In summary, the designed THz-metasurface biosensor not only possesses advantages including low detection limit, high integration, and high automation, but also has a bright application prospect in the biomedical field, bringing hope to many patients suffering from illness.