title: Polymer-coated fluorescent CdSe-based quantum dots for application in immunoassay.
abstract: The paper describes all stages of synthesis and characterization of biocompatible CdSe-based core/shell quantum dots (QDs) and their application as fluorescent label for immunoassay. Special attention was focused on development of maleic anhydride-based amphiphilic polymers for QDs solubilization in aqueous media. In this work two PEG-amines were tried for polymer modification: monoamine Jeffamine M 1000 used previously in some researches and diamine Jeffamine ED-2003 applied for the first time for QDs solubilization. The use of different Jeffamines allows us to obtain QDs with carboxyl or amine functional groups available for conjugation. The influence of polymer composition on optical properties of the nanocrystals and their stability in aqueous solutions as well as on their conjugation with biomolecules was studied. QDs with different coatings were used as biolabels in quantitative fluorescence microtiter plate immunoassay and qualitative on-site column test. It was found that quantum dots covered with amphiphilic polymer prepared from poly(maleic anhydride-alt-1-octadecene) and Jeffamine ED-2003 retained up to 90% of their initial brightness, easily conjugated with protein and showed low non-specific adsorption. In optimized conditions the obtained QDs were successfully used for determination of mycotoxin deoxynivalenol in wheat and maize samples by fluorescence microtiter plate immunoassay with an IC50 of 220 μg kg(-1) and by on-site column test with cut-off of 500 μg kg(-1).
authors.affiliation: Department of General and Inorganic Chemistry, Chemistry Institute, Saratov State University, Astrakhanskaya 83, 410012 Saratov, Russia; Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium. Electronic address: Elena.Speranskaya@UGent.be.
authors.forename: Elena S
authors.initials: ES
authors.lastname: Speranskaya
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Beloglazova
authors.forename: Pieterjan
authors.initials: P
authors.lastname: Lenain
authors.forename: Sarah
authors.initials: S
authors.lastname: De Saeger
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Wang
authors.forename: Suxia
authors.initials: S
authors.lastname: Zhang
authors.forename: Zeger
authors.initials: Z
authors.lastname: Hens
authors.forename: Dietmar
authors.initials: D
authors.lastname: Knopp
authors.forename: Reinhard
authors.initials: R
authors.lastname: Niessner
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Potapkin
authors.forename: Irina Yu
authors.initials: IY
authors.lastname: Goryacheva
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D006801:Humans; D007118:Immunoassay; D009183:Mycotoxins / Q000302:isolation & purification*; D053758:Nanoparticles / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D009183:Mycotoxins; D011108:Polymers; D014867:Water; D011092:Polyethylene Glycols
keywords: Amphiphilic polymers; Deoxynivalenol; Fluorescent nanoparticles; Immunoassay; Quantum dots