Terahertz biochemical sensor based on multiparameter metasurface for molecular fingerprint detection

•Our manuscript develops a fingerprint spectrum sensing platform based on a dual resonance device that can determine the analytes as well as the concentration from the frequency shift and amplitude change of the two resonance dips at different polarization modes and angles of incidence.•Our technology allows the multi-dimensional characterization of analytes for fingerprint spectrum sensing without introducing antibodies and replacing metasurfaces, providing a convenient and versatile platform for biochemical sensing. Terahertz (THz) label-free metasurface sensors have attracted great attention in the biochemical field, and fingerprint spectral sensing provides a powerful tool for the detection of trace analytes. In this study, we demonstrated a method based on a dual resonance metasurface sensor that enabled the identification of α-lactose, cis-azobenzene (cis-AB), and trans-azobenzene (trans-AB), as well as their concentration detection. By changing the angle of incidence and direction of polarization of THz wave on the metasurface covering analyte, the double resonance dips would be changed, and the spectral changes due to the changes in these parameters would be summarized on the radargrams, the sensor provided different THz fingerprint spectrums for each sample even without introducing antibodies. Our results provide a convenient route for fingerprint spectrum identification of biochemical molecules.