title: Electrochemical sensing platform based on polyelectrolyte-surfactant supramolecular assemblies incorporating carbon nanotubes.
abstract: The characterization and application of a polyelectrolyte-surfactant supramolecular assembly formed by poly(allylamine) and dodecyl sulfate (PA-DS) on a screen-printed graphite electrode for the preparation of electrochemical sensing platforms are presented. The system was characterized by X-ray reflectometry (XRR) and grazing-incidence small-angle X-ray scattering (GISAXS) and tested with four benchmark electrochemical probes undergoing different electron-transfer mechanisms on carbon: ferrocyanide, hexaammineruthenium, ascorbic acid, and dopamine. The polyelectrolyte acts as a scaffold favoring the incorporation of the ferrocyanide, an ion oppositely charged to poly(allylamine). Also, its ability to incorporate carbon nanotubes (CNT) is presented. The composite material PA-DS-CNT is able to electrocatalyze the oxidation of dopamine, allowing its detection at micromolar levels in the presence of 100 times higher concentrations of ascorbate and it is shown to be stable, while XRR and GISAXS results confirm a lamellar structure with well-defined domains, not perturbed by the presence of the CNT. The dispersion is easily prepared in aqueous solution and could facilitate the processing of the CNT with an efficient loading and yielding a more robust carbon-based material for sensing applications.
authors.affiliation: INQUIMAE, Departamento Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires, Argentina.
authors.forename: M Lorena
authors.initials: ML
authors.lastname: Cortez
authors.forename: Marcelo
authors.initials: M
authors.lastname: Ceolín
authors.forename: Omar
authors.initials: O
authors.lastname: Azzaroni
authors.forename: Fernando
authors.initials: F
authors.lastname: Battaglini