title: Separation of alpha-lactalbumin grafted- and non-grafted maghemite core/silica shell nanoparticles by capillary zone electrophoresis.
abstract: The use of nanoparticles (NPs) in immunodiagnostics is a challenging task for many reasons, including the need for miniaturization. In view of the development of an assay dedicated to an original, miniaturized and fully automated immunodiagnostics which aims to mimic in vivo interactions, magnetic zwitterionic bifunctional amino/polyethyleneoxide maghemite core/silica shell NPs functionalized with allergenic alpha-lactalbumin were characterized by CE. Proper analytical performances were obtained through semi-permanent capillary coating with didodecyldimethylammonium bromide (DDAB) or permanent capillary wall modification by hydroxypropylcellulose. The influence of experimental conditions (e.g. buffer component nature, pH, ionic strength, and electric field strength) on sample stability, electrophoretic mobility, and dispersion was investigated using either DDAB- or hydroxypropylcellulose-coated capillaries. Adsorption to the capillary wall and aggregation phenomena were evaluated according to the CE conditions. The proper choice of experimental conditions, i.e. separation under -10 kV in a 25 mM ionic strength MES/NaOH (pH 6.0) with a DDAB-coated capillary, allowed the separation of the grafted and the non-grafted NPs.
authors.affiliation: Laboratory of Physicochemistry of Electrolytes, Colloids and Analytical Sciences (PECSA), UMR CNRS 7195, Ecole Nationale Supérieure de Chimie de Paris (Chimie ParisTech), Paris, France.
authors.forename: Jan
authors.initials: J
authors.lastname: Petr
authors.forename: Bruno
authors.initials: B
authors.lastname: Teste
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Descroix
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Siaugue
authors.forename: Pierre
authors.initials: P
authors.lastname: Gareil
authors.forename: Anne
authors.initials: A
authors.lastname: Varenne
mesh_terms: D002197:Capillary Action; D004355:Drug Stability; D019075:Electrophoresis, Capillary / Q000379:methods*; D005290:Ferric Compounds; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D058085:Iron Compounds; D007768:Lactalbumin / Q000737:chemistry / Q000302:isolation & purification*; D053758:Nanoparticles / Q000737:chemistry*; D009994:Osmolar Concentration; D000644:Quaternary Ammonium Compounds; D013816:Thermodynamics
chemical_list: D005290:Ferric Compounds; D007202:Indicators and Reagents; D058085:Iron Compounds; D000644:Quaternary Ammonium Compounds; C046112:didodecyldimethylammonium; C000499:ferric oxide; D007768:Lactalbumin