title: High-performance liquid chromatography assay of cysteine and homocysteine using fluorosurfactant-functionalized gold nanoparticles as postcolumn resonance light scattering reagents.
abstract: Herein, a new postcolumn resonance light scattering (RLS) detection approach coupled with high-performance liquid chromatography (HPLC) was developed to detect cysteine and homocysteine. In the established system, the fluorosurfactant-capped gold nanoparticles (AuNPs) were first employed as postcolumn RLS reagents. The detection principle was based on the enhancement of RLS intensity of AuNPs upon the addition of cysteine/homocysteine. The RLS signals were detected by a common fluorescence detector at λ(EX)=λ(EM)=560 nm. The linear ranges for both cysteine and homocysteine were in the range of 5.0-50 μM. The detection limits were 5.9 pmol for cysteine and 12 pmol for homocysteine at a signal-to-noise ratio of 3. HPLC separation and RLS detection conditions were optimized in detail. The applicability of the proposed method has been validated by detecting cysteine and homocysteine in human urine samples. Recoveries from spiked urine samples were 95.0-103.0%.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Qunyan
authors.initials: Q
authors.lastname: Xiao
authors.forename: Huiling
authors.initials: H
authors.lastname: Gao
authors.forename: Qipeng
authors.initials: Q
authors.lastname: Yuan
authors.forename: Chao
authors.initials: C
authors.lastname: Lu
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D003545:Cysteine / Q000652:urine*; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D006710:Homocysteine / Q000652:urine*; D006801:Humans; D007202:Indicators and Reagents; D008027:Light; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012542:Scattering, Radiation
chemical_list: D007202:Indicators and Reagents; D006710:Homocysteine; D006046:Gold; D003545:Cysteine