The theory, technology, and application of terahertz metamaterial biosensors: A review

Terahertz metamaterial biosensors combine terahertz time-domain spectroscopy with metamaterial sensing to provide a sensitive detection platform for a variety of targets, including biological molecules, proteins, cells, and viruses. These biosensors are characterized by their rapid response, sensitivity, non-destructive, label-free operation, minimal sample requirement, and user-friendly design, which also allows for integration with various technical approaches. Advancing beyond traditional biosensors, terahertz metamaterial biosensors facilitate rapid and non-destructive trace detection in biomedical applications, contributing to timely diagnosis and early screening of diseases. In this paper, the theoretical basis and advanced progress of these biosensors are discussed in depth, focusing on three key areas: improving the sensitivity and specificity, and reducing the influence of water absorption in biological samples. This paper also analyzes the potential and future development of these biosensors for expanded applications. It highlights their potential for multi-band tuning, intelligent operations, and flexible, wearable biosensor applications. This review provides a valuable reference for the follow-up research and application of terahertz metamaterial biosensors in the field of biomedical detection.