Metal organic framework UiO-66 functionalized terahertz metasurface for detection of biomarker 2-pentanone.

2-Pentanone has attracted increasing attention as a potential biomarker for several diseases, highlighting the demand for rapid, selective, and noninvasive detection. Here, we present a UiO-66-functionalized terahertz metasurface comprising two S-shaped split-ring resonators and an antenna, which supports three physically distinct resonance modes. Simulation results reveal high sensitivities of 52.5, 85.5, and 99 GHz/RIU (refractive index unit) at the respective resonances. To enhance analyte uptake and generate measurable multimode responses, the metasurface was functionalized with UiO-66 through a robust multilayer assembly strategy. Across the investigated 20-200 ppm range, all three modes exhibited concentration-dependent red shifts, with a maximum shift of 14.62 GHz at 200 ppm. The highest-frequency mode provided the largest linewidth-normalized response (Δf/FWHM = 0.3864). The results demonstrate that the MOF-functionalized metasurface has potential application for development of intelligent sensing systems based on multidimensional optical information and pattern-recognition techniques.