title: In-capillary non-covalent labeling and determination of tomato systemin with quantum dots in capillary electrophoresis with laser-induced fluorescence detection.
abstract: Quantum dots (QDs), with their superior size-dependent fluorescence properties, have been employed as non-covalent fluorescent labels for the determination of tomato systemin (TomSys) by capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection. The optimum conditions of in-capillary labeling and CE separation were investigated in detail, and complete separation of QDs-labeled TomSys from free QDs labels was achieved. Satisfactory results were obtained in terms of linearity (R(2)=0.998), sensitivity (limit of detection, 66 fmol) and repeatability (run-to-run RSDs of migration time and peak area, 0.9 and 4.6%, respectively; day-to-day RSDs of migration time and peak area, 3.1 and 11.9%, respectively). The established CE-LIF method was later applied in the detection of TomSys spiked in the sample of tomato leaves, which showed the applicability of the proposed method in the analysis of the target plant peptide hormone in the complex matrix.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.forename: Fuyou
authors.initials: F
authors.lastname: Du
authors.forename: Youyou
authors.initials: Y
authors.lastname: Yang
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.forename: Huwei
authors.initials: H
authors.lastname: Liu
mesh_terms: D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D007834:Lasers; D018551:Solanum lycopersicum / Q000737:chemistry*; D010455:Peptides / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis*; D045663:Quantum Dots; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods*
chemical_list: D010455:Peptides; D010936:Plant Extracts; C073704:systemin