Chiral identification of tyrosine enantiomers based on an achiral terahertz metamaterial sensor

Tyrosine (Tyr) is an important aromatic amino acid involved in various physiological processes and associated with research into disease mechanisms. Its enantiomers may differ in origin, metabolic pathways, and biological effects, but due to their similar conformations and subtle response differences, accurate differentiation of Tyr enantiomers is challenging yet crucial. Based on the characteristic fingerprint spectra of Tyr, this paper designs an achiral terahertz electromagnetically induced transparency (EIT) metamaterial sensor and develops a label-free detection method for terahertz chiral sensing of Tyr. By extracting chiral parameters from the circular polarization transmission coefficients, we analyze the coupling mechanism between Tyr and the sensor, further revealing its recognition principle. The EIT effect is utilized to amplify the difference in chiral responses between enantiomers. The Freundlich model is adopted to fit the experimental data, and the limit of detection (LOD) is 0.01 mg/mL. The proposed sensor enables specific detection and enantiomer recognition of Tyr. This method can also be extended to other chiral biological samples, demonstrating great potential in biomedical applications, food safety detection, and environmental monitoring.