Terahertz metasurfaces covered Weyl semimetal nanofilms for nondestructive detection of antibiotics

Abstract

This study presents a simply method in antibiotic detection through the integration of terahertz (THz) metasurfaces with Weyl semimetal nanofilms, offering a highly sensitive and non-destructive analytical approach. The core innovation lies in the synergistic interaction between the engineered electromagnetic properties of the metasurface and the unique topological electronic states of Weyl semimetals, which enhances THz radiation-molecule interactions via two key mechanisms: localized field amplification and shift-current photoresponse. Using a 0.1 THz continuous-wave source combined with a microcurrent probe platform, the system achieved sub-nanogram per milliliter detection limits for metronidazole. For three representative antibiotics (metronidazole, norfloxacin, and chloramphenicol) across a concentration range of 0.1–10⁷ ng/L, detection signals exhibited strong linear correlations with concentrations, with respective limits of 0.08 ng/L, 0.06 ng/L, and 8 ng/L—markedly surpassing those of conventional methods (e.g., microbiological assays, HPLC, and LC-MS/MS). This methodology distinguishes itself through its rapid detection (minutes per sample), operational simplicity (avoiding complex spectral deconvolution), and high reproducibility, while preserving sample integrity due to its non-contact nature. The integration of Weyl semimetal films further enhances photoelectric conversion efficiency, enabling ultra-sensitive responses even at low power densities.With these advancements, the platform holds promising applications in precise medical diagnostics, environmental pollutant monitoring, and pharmaceutical quality control, paving the way for widespread adoption in fields requiring ultrasensitive, non-invasive trace analysis.