Abstract
We performed label-free detection of β-lactoglobulin and compared sensitivity of metallic mesh sensors with different size of periodic structure. Since transmission property of the metallic mesh is affected by refractive index around openings, application for a refractive index sensor has also been studied. In this work, 3 types of metallic meshes (estimated resonance frequency at 3, 10 and 40THz) were prepared and β-lactoglobulin was fixed on the surface of the metallic mesh. We succeeded to acquire transmission property of metallic meshes performed in mid-infrared using 7-µm grid constant and 50 times higher sensitivity than 3THz mesh (76-µm grid constant). The result suggests small scale of periodic structure is advantageous for applications such as trace detection of protein reaction.
