title: Magnetic Fe2O3-polystyrene/PPy core/shell particles: bioreactivity and self-assembly.
abstract: This paper describes the synthesis of new magnetic, reactive polystyrene/polypyrrole core/shell latex particles. The core consists of a polystyrene microsphere containing gamma-Fe2O3 superparamagnetic nanoparticles (PSmag), and the shell is made of reactive N-carboxylic acid-functionalized polypyrrole (PPyCOOH). These PSmag-PPyCOOH latex particles, average diameter 220 nm, were prepared by copolymerization of pyrrole (Py) and the active carboxyl-functionalized pyrrole (PyCOOH) in the presence of PSmag particles. PNVP was used as a steric stabilizer. The functionalized polypyrrole-coated PSmag particles were characterized in terms of their particle size, surface morphology, chemical composition, and electrochemical and magnetic properties using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry, and SQUID magnetometry. Activation of the particle surface carboxyl groups was achieved using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS), which helps transform the carboxyl groups into activated ester groups (NSE). The activated particles, PSmag-PPyNSE, were further evaluated as bioadsorbents of biotin used as a model biomolecule. It was shown that biotin was immobilized at the surface of the PSmag-PPyNSE particles by forming interfacial amide groups. The assemblies of PSmag-PPyCOOH particles on glass plates were further investigated. When no magnetic field is applied, the particles assemble into 3D colloidal crystals. In contrast, under a magnetic field, one-particle-thick chains gathered in hedgehog-like architectures are obtained. Furthermore, PSmag-PPyCOOH coated ITO electrodes were shown to be electroactive and electrochemically stable, thus offering potentialities for creating novel high-specific-area materials for biosensing devices where the conducting polymer component would act as the transducer through its conductive properties.
authors: Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS), Université Paris 7 Denis Diderot, CNRS (UMR 7086), 1 rue Guy de la Brosse, 75005 Paris, France. mangeney@paris7.jussieu.fr
authors: Claire
authors: C
authors: Mangeney
authors: Meriem
authors: M
authors: Fertani
authors: Smain
authors: S
authors: Bousalem
authors: Ma
authors: M
authors: Zhicai
authors: Souad
authors: S
authors: Ammar
authors: Fréderic
authors: F
authors: Herbst
authors: Patricia
authors: P
authors: Beaunier
authors: Abdelhamid
authors: A
authors: Elaissari
authors: Mohamed M
authors: MM
authors: Chehimi
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D020099:Coated Materials, Biocompatible; D004563:Electrochemistry; D005290:Ferric Compounds / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D005290:Ferric Compounds; D011108:Polymers; D011137:Polystyrenes; D011758:Pyrroles; C000499:ferric oxide; C067635:polypyrrole