title: Multi-targeting single fiber-optic biosensor based on evanescent wave and quantum dots.
abstract: Highly sensitive, multi-analyte assay is a long-standing challenge for a single fiber-optic evanescent wave biosensor (FOB). In this paper, we report the first realization of such kind of FOB using CdSe/ZnS core/shell quantum dots (QDs) as labels. A direct binding assay model between antibody and antigen was employed to demonstrate the advantages of using QDs, instead of conventional fluorescein isothiocyanate (FITC), in lifting the sensitivity. Especially, multiplexed immunoassay was demonstrated in a single fiber FOB constructed with four differently sized QDs. Furthermore, the phenomenon that the affinity of the QD-labeled human IgG (QD-IgG) with goat anti-human IgG (anti-IgG) was lower than that of the FITC-labeled human IgG (FITC-IgG) was investigated and was ascribed to the differences in size and mass of the two. Our study indicates that the affinity could be improved by controlling the amount of IgG binding on QDs.
authors.affiliation: Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
authors.forename: Youlin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qinghui
authors.initials: Q
authors.lastname: Zeng
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Sun
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Liu
authors.forename: Langping
authors.initials: L
authors.lastname: Tu
authors.forename: Xianggui
authors.initials: X
authors.lastname: Kong
authors.forename: Wybren Jan
authors.initials: WJ
authors.lastname: Buma
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology*; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*
chemical_list: D007074:Immunoglobulin G