Non-labeling Detection by Terahertz Surface Plasmon Resonance of Topological Insulator Bi2(Se, Te)3

Terahertz (THz) wave, corresponding to intermolecular binding energy, is the key to realizing a non-labeling bio-medical sensor. To use topological insulators for THz surface plasmon resonance, we aim to enhance the sensitivity by a selective resonant excitation effect of the specific chemical binding and surface plasmon at the THz band. Here, we report the THz-SPR of Bi
2
Se
2
Te, which has fewer lattice defects than Bi
2
Se
3
. Bi
2
Se
2
Te was processed in a micro ribbon array to enhance SPR in the THz range. The avidin-biotin specific binding was observed due to the enhancement of THz-SPR with Bi
2
Se
2
Te.