Non-Covalent Functionalization of Multi-Wall Carbon Nanotubes with Polyarginine: Characterization and Analytical Applications for Uric Acid Quantification

ALEJANDRO GUTIERREZ; FABIANA GUTIERREZ; MARCOS EGUILAZ; GUSTAVO A. RIVAS

ELECTROANALYSIS

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2018 vol. 30 p. 1 - 1

1040-0397

bstract: We report for the first time the non-covalentfunctionalization of multiwall carbon nanotubes(MWCNTs) with polyarginine (Polyarg), the modificationof glassy carbon electrodes (GCE) with the resultingPolyarg-MWCNTs dispersion and the analytical applicationof Polyarg-MWCNTs-modified GCE for the quantificationof uric acid. The optimum MWCNT-Polyargdispersion was obtained by sonicating for 5.0 min themixture of 0.75 mgmL1 MWCNTs and 0.50 mgmL1Polyarg. The dispersion was characterized by scanningelectron microscopy, electrophoretic mobility, electrochemicalimpedance spectroscopy, cyclic voltammetry andamperometry. The presence of MWCNT-Polyarg at GCEsurface produced a drastic decrease in the overvoltages for the oxidation of hydrogen peroxide (300 mV) ascorbicacid (281 mV) and uric acid (70 mV) and for the reductionof hydrogen peroxide (200 mV), as well as an importantdecrease in the charge transfer resistances for hydrogenperoxide, hydroquinone/quinone and ferricyanide/ferrocyanid