title: Improving immunosensor performance through oriented immobilization of antibodies on carbon nanotube composite surfaces.
abstract: We report the straightforward oriented covalent attachment of antibodies (Abs) on the surface of carboxylated multiwalled carbon nanotube-polystyrene (MWCNT-PS) materials. The combination of this composite material, applied as a robust electrochemical transducer platform, and its covalent functionalization with Abs in a controlled way by means of a two-step process, could contribute to the development of highly sensitive immunosensor devices. Using the simple and versatile carbodiimide chemistry, Abs were attached to the carboxylic groups of the MWCNT-PS composite surfaces via their superficial amine groups. By taking into account the Ab isoelectric point and the net charge of the composite surface, we engineered an immobilization process to achieve the oriented binding of the Ab molecules by favoring an ionic pre-adsorption step before covalent binding occurred. Thus, the antigen binding capacity of the attached Abs was enhanced by up to 10 times with respect to the capacity estimated for a random spatial distribution of these molecules. The proposed strategy would also serve as a model for the efficient biofunctionalization of other carboxylated carbon-based polymer composite materials with potential applications in the biosensor field.
authors: Biofunctionalization of Nanoparticles and Surfaces (BioNanoSurf), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza. Campus Río Ebro, Edifício I+D, Mariano Esquillor, s/n, 50018 Zaragoza, Spain. selmer@unizar.es
authors: Sara
authors: S
authors: Puertas
authors: María
authors: M
authors: de Gracia Villa
authors: Ernest
authors: E
authors: Mendoza
authors: Cecilia
authors: C
authors: Jiménez-Jorquera
authors: Jesús M
authors: JM
authors: de la Fuente
authors: César
authors: C
authors: Fernández-Sánchez
authors: Valeria
authors: V
authors: Grazú
mesh_terms: D000327:Adsorption; D000906:Antibodies / Q000737:chemistry* / Q000648:ultrastructure; D001665:Binding Sites; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D011485:Protein Binding; D013499:Surface Properties
chemical_list: D000906:Antibodies; D037742:Nanotubes, Carbon