Highly sensitive detection in electrophoretic separations using gold nanoparticles and thermal lens microscopy

ANYL 308

Yoshihiro Akimoto, Yukihiro Okamoto, Fumihiko Kitagawa, and Koji Otsuka, otsuka@mbox.kudpc.kyoto-u.ac.jp. Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
The use of gold nanoparticles (GNPs) in capillary electrophoresis (CE) with thermal lens microscope (TLM) detection was investigated as a highly sensitive detection scheme. The GNP was used as a specific supporting material. Since the surface plasmon resonance absorption of the GNP exhibits a sensitive response toward an environmental change, sensitive detection of non-absorbing species is expected. By using a background solution containing the GNPs in CE-TLM, a successful label-free detection of several amino acids was achieved. A good linear relationship between the peak area of glutamic acid and its concentration was observed. Fundamental characteristics of GNP-CE-TLM will be discussed. In microchip electrophoresis (MCE) using a cycloolefin polymer chip, TLM was also employed as a high-sensitive detection method. A fast chiral separation and protein analysis of rat serum by MCE-TLM were demonstrated in combination with sweeping as an on-line sample concentration method by using electrokinetic chromatography (EKC) modes.