Terahertz biochemical sensor based on multiparameter metasurface for molecular fingerprint detection

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.