title: Novel electrochemical sensor based on N-doped carbon nanotubes and Fe3O4 nanoparticles: simultaneous voltammetric determination of ascorbic acid, dopamine and uric acid.
abstract: A new modified electrode based on N-doped carbon nanotubes functionalized with Fe3O4 nanoparticles (Fe3O4@CNT-N) has been prepared and applied on the simultaneous electrochemical determination of small biomolecules such as dopamine (DA), uric acid (UA) and ascorbic acid (AA) using voltammetric methods. The unique properties of CNT-N and Fe3O4 nanoparticles individually and the synergetic effect between them led to an improved electrocatalytic activity toward the oxidation of AA, DA and UA. The overlapping anodic peaks of these three biomolecules could be resolved from each other due to their lower oxidation potentials and enhanced oxidation currents when using the Fe3O4@CNT-N modified electrode. The linear response ranges for the square wave voltammetric determination of AA, DA and UA were 5-235, 2.5-65 and 2.5-85μmoldm(-3) with detection limit (S/N=3) of 0.24, 0.050 and 0.047μmoldm(-3), respectively. These results show that Fe3O4@CNT-N nanocomposite is a promising candidate of cutting-edge electrode materials for electrocatalytic applications.
authors.affiliation: REQUIMTE/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal. Electronic address: diana.fernandes@fc.up.pt.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Fernandes
authors.affiliation: REQUIMTE/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Costa
authors.affiliation: REQUIMTE/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: Clara
authors.initials: C
authors.lastname: Pereira
authors.affiliation: Instituto de Catálisis y Petroleoquímica, CSIC, C/ Marie Curie 2, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Bachiller-Baeza
authors.affiliation: Instituto de Catálisis y Petroleoquímica, CSIC, C/ Marie Curie 2, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Rodríguez-Ramos
authors.affiliation: Dpto. de Química Inorgánica y Química Técnica, Facultad de Ciencias, UNED, Senda del Rey 9, 28040 Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Guerrero-Ruiz
authors.affiliation: REQUIMTE/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal. Electronic address: acfreire@fc.up.pt.
authors.forename: Cristina
authors.initials: C
authors.lastname: Freire
keywords: Ascorbic acid; Carbon nanotubes; Dopamine; Fe(3)O(4) magnetic nanoparticles; Uric acid