Label-free THz sensing of living body-related molecular binding using a metallic mesh

► We demonstrate dip frequency shifts by permittivity changes in FDTD simulations. ► We demonstrate quantitatively label-free THz sensing of the lectin-sugar interaction. ► The binding constant between Con-A and Glc is derived experimentally by THz sensing. ► We demonstrate qualitatively label-free THz sensing of the lectin-sugar interaction. ► We demonstrate high-sensitive THz sensing of the avidin-biotin interaction.