title: Quinone-rich poly(dopamine) magnetic nanoparticles for biosensor applications.
abstract: Novel core-shell quinone-rich poly(dopamine)-magnetic nanoparticles (MNPs) were prepared by using an in situ polymerization method. Catechol groups were oxidized to quinone by using a thermal treatment. MNPs were characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, magnetic force microscopy, UV/Vis, Fourier-transform infrared spectroscopy, and electrochemical techniques. The hybrid nanomaterial showed an average core diameter of 17 nm and a polymer-film thickness of 2 nm. The core-shell nanoparticles showed high reactivity and were used as solid supports for the covalent immobilization of glucose oxidase (Gox) through Schiff base formation and Michael addition. The amount of Gox immobilized onto the nanoparticle surface was almost twice that of the nonoxidized film. The resulting biofunctionalized MNPs were used to construct an amperometric biosensor for glucose. The enzyme biosensor has a sensitivity of 8.7 mA M(-1)  cm(-2) , a low limit of detection (0.02 mM), and high stability for 45 days. Finally, the biosensor was used to determine glucose in blood samples and was checked against a commercial glucometer.
authors.affiliation: Neurochemistry and Neuroimaging group, Faculty of Medicine, University of La Laguna, Campus de Ofra s/n, 38071 La Laguna, Tenerife (Spain).
authors.forename: Miriam
authors.initials: M
authors.lastname: Martín
authors.forename: Alejandro
authors.initials: A
authors.lastname: González Orive
authors.forename: Pablo
authors.initials: P
authors.lastname: Lorenzo-Luis
authors.forename: Alberto
authors.initials: A
authors.lastname: Hernández Creus
authors.forename: José Luis
authors.initials: JL
authors.lastname: González-Mora
authors.forename: Pedro
authors.initials: P
authors.lastname: Salazar
mesh_terms: D015374:Biosensing Techniques; D005947:Glucose / Q000032:analysis / Q000378:metabolism; D005949:Glucose Oxidase / Q000378:metabolism*; D007211:Indoles / Q000737:chemistry* / Q000378:metabolism; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D011809:Quinones / Q000737:chemistry* / Q000378:metabolism
chemical_list: D007211:Indoles; D058185:Magnetite Nanoparticles; D011108:Polymers; D011809:Quinones; C568283:polydopamine; D005949:Glucose Oxidase; D005947:Glucose
keywords: biosensors; glucose oxidase; magnetic properties; nanoparticles; natural products