LSPR Sensitivity Improvement by Using CNTs/Au Nanoparticle for Bioanalysis

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, and aim at two points of the establishment of a new LSPR sensor and the detection of the antigen of the low density. As study process, CNTswere 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 absorption. BSA of 100mg/l as a protein was applied to the absorption test. Absorption spectra of before and after were compared by the LSPR analysis. Especially, to improve the sensitivity of LSPR,CNTs was patterned by the lithography. After BSA adhesion, in patterned CNTs substrate,it was seen that wavelength shifted by about 7 nm. Therefore, we were able to confirm thatthe substrate which was allocated metal particles in three dimensions had the function as the sensor, and had a potential to improve sensitivity of LSPR.