title: Selective enrichment of aminothiols using polysorbate 20-capped gold nanoparticles followed by capillary electrophoresis with laser-induced fluorescence.
abstract: In this article, we report a simple method for selective enrichment of aminothiols using Tween 20-capped gold nanoparticles (AuNPs) prior to capillary electrophoresis coupled with laser-induced fluorescence (CE-LIF). Compared to citrate-capped AuNPs, Tween 20-capped AuNPs exhibit the ability to disperse in a highly saline solution and selectively extract aminothiols through the formation of Au-S bonds. After extraction and centrifugation, 1mM thioglycollic acid (TGA) was utilized to remove aminothiols that attached to the NP surfaces. After a solution of 8.0 mL aminothiols were extracted using 2x AuNPs (200 microL), the extracted aminothiols derivatized with o-phthalaldehyde at pH 12.0 were detected by CE-LIF. As a result, the limits of detection at a signal-to-noise ratio of 3 for homocysteine (HCys), glutathione (GSH), and gamma-glutamycysteine (Glu-cys) are 4013.2, 79.8, and 382.8 pM, respectively. The use of this probe provided approximately 11-, 282-, and 21-fold sensitivity improvements for HCys, GSH, and Glu-cys, respectively. A practical analysis of HCys, GSH, and Glu-cys in human urine sample has been accomplished by this present method.
authors.affiliation: Department of Chemistry, National Sun Yat-sen University, 70, Lien-hai Road, Kaohsiung 804, Taiwan.
authors.forename: Chien-Chih
authors.initials: CC
authors.lastname: Shen
authors.forename: Wei-Lung
authors.initials: WL
authors.lastname: Tseng
authors.forename: Ming-Mu
authors.initials: MM
authors.lastname: Hsieh
mesh_terms: D000603:Amino Acids, Sulfur / Q000032:analysis* / Q000652:urine; D004151:Dipeptides / Q000032:analysis / Q000652:urine; D019075:Electrophoresis, Capillary / Q000379:methods*; D005453:Fluorescence; D005978:Glutathione / Q000032:analysis / Q000652:urine; D006046:Gold / Q000737:chemistry*; D006710:Homocysteine / Q000032:analysis / Q000652:urine; D006801:Humans; D007834:Lasers; D016014:Linear Models; D053768:Metal Nanoparticles / Q000737:chemistry*; D011136:Polysorbates / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D009764:o-Phthalaldehyde / Q000737:chemistry
chemical_list: D000603:Amino Acids, Sulfur; D004151:Dipeptides; D011136:Polysorbates; D006710:Homocysteine; D009764:o-Phthalaldehyde; D006046:Gold; D005978:Glutathione; C017341:gamma-glutamylcysteine