title: Label-free detection of amino acids using gold nanoparticles in electrokinetic chromatography-thermal lens microscopy.
abstract: To achieve label-free detection of amino acids in capillary-based electrokinetic chromatography-thermal lens microscopy (EKC-TLM), gold nanoparticles (GNPs), which possess the absorption around 500nm attributed to surface plasmon resonance (SPR), were added to the background solution (BGS). Since the SPR absorption of the GNPs exhibits a sensitive response toward environmental changes and the degree of aggregation, the sensitive detection of non-absorbing species is expected by using the GNPs in EKC-TLM (GNP-EKC-TLM). In the GNP-EKC-TLM analysis of glutamic acid (Glu), a sharp peak was observed when the GNPs were added to the BGS. The plot of the peak area of Glu against its concentration gave a good linear relationship and the limit of detection was estimated to be 25mug/mL. Furthermore, a baseline separation of lysine and Glu was successfully achieved. Thus, the EKC separation and label-free TLM detection of the amino acids can be realized only by adding the GNPs into the BGSs.
authors: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors: Fumihiko
authors: F
authors: Kitagawa
authors: Yoshihiro
authors: Y
authors: Akimoto
authors: Koji
authors: K
authors: Otsuka
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000302:isolation & purification; D053801:Capillary Electrochromatography / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008853:Microscopy / Q000379:methods*; D020349:Surface Plasmon Resonance
chemical_list: D000596:Amino Acids; D006046:Gold