Terahertz sensing method for protein detection using a thin metallic mesh

A label-free biological sensor, which is based on the resonant transmission phenomenon of a thin metallic mesh, is proposed in the terahertz wave region. By using this sensor, we demonstrate the highly sensitive detection of small amounts of protein horseradish peroxidase. For quantitative investigation of the sensitivity of our sensor, horseradish peroxidase was printed on the metallic mesh surface by using a commercial available printer. A distinct shift of the transmission dip frequency is observed for 500 pg ∕ mm 2 ( 11 fmol ) of horseradish peroxidase printed on the metallic mesh, indicating the significantly high sensitivity of our sensor.