The Fabrication and Function Evaluation of 3D LSPR Biosensor by using CNTs/Au Nanoparticles

Abstract

In the conventional sensor using localized surface Plasmon resonance (LSPR), metallic particle has been only allocated on substrate in two dimensions. We attempt to allocate metal particles in three dimensions to improve sensitivity than a conventional LSPR sensor. As study process, CNTs were synthesized on the Si substrate as support by the CVD method, and modifying gold nanoparticles on surface of CNTs by the PVD method. Evaluation of applicability to bio-sensor was carried out by using protein adsorption. BSA as a protein was applied to the adsorption test. To improve the sensitivity of LSPR, CNTs was patterned by the lithography. Then structural size (Diameter and Pitch) was changed by lithography. For establishment of a new LSPR sensor, we design the optimal structure of detection of low concentration antigen. After BSA adhesion, narrower diameter and pitch of patterned CNTs, longer shift amount was confirmed. And, when Au deposition angle changed (θ: 0→45), shift amount was increased. Therefore, we were able to confirm that the substrate which was allocated metal particles in three dimensions had the function as the sensor, and had a potential to improve LSPR sensitivity by optimal design of CNTs patterning.