부산대학교 도서관

Here, we present a novel flexible terahertz (THz) biosensor consisting of electromagnetic-induced transparency-like metasurfaces and a GaN/graphene van der Waals heterostructure (vdWH), which can achieve multidimensional ultrasensitive detection of aspartic acid. The proposed biosensor could detect the concentration limit of aspartic acid with a 10.6 fg/mL by the change in transmission amplitude, phase difference, and group delay. This internal mechanism can be explained by the change in the energy band structure of the vdWH with different concentrations of aspartic acid. As the concentration of aspartic acid increases, the conduction band of GaN approaches the Fermi level, and the Fermi level of graphene changes, resulting in variations in THz of transmission amplitude, phase difference, and group delay. In addition, we used the coupled harmonic oscillator mode to explain the sensing mechanism. This study provides a new method for the sensing of trace elements.