Terahertz metasurface sensor based on patterned metal slit structure for trace detection

Food safety and substance identification have always been an important issue in trace detection research. In this study, a terahertz metasurface sensor based on a patterned metal slit structure is proposed. The two transmission modes of the sensor can not only be used to detect trace samples, but also achieve specific trace detection for terahertz fingerprint spectra of specific samples. Experimental results demonstrate that the sensor enables highly sensitive and non-destructive trace detection of potassium sorbate under both transmission modes. Furthermore, in the simulation results of TM transmission mode, the metasurface sensor can produce electromagnetic absorption induced transparency effect with the characteristic fingerprint peak of L-arginine at 0.99 THz, and realize the non-destructive specific recognition of L-arginine. This work provides a novel strategy for terahertz sensing and contributes to the development of qualitative and quantitative detection techniques in biomedicine, food safety, and pharmaceutical analysis.