Quantification of quercetin using glassy carbon electrodes modified with multiwalled carbon nanotubes dispersed in polyethylenimine and polyacrylic acid.

FABIANA GUTIERREZ; GABRIELA ORTEGA; JOSÉ LUIS CABRERA; MARÍA D. RUBIANES; GUSTAVO A. RIVAS

ELECTROANALYSIS

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2010 vol. 22 p. 2650 - 2657

1040-0397

This work reports the highly sensitive detection of quercetin using glassy carbon electrodes modified with multiwall carbon nanotubes (MWCNT) dispersed in polyethylenimine and poly(acrylic acid). The adsorptive stripping with square wave voltammetric transduction allowed the detection of 7.5 nM quercetin after 1.0 min accumulation at open circuit potential. The amperometric detection at 0.150 V is reported as an easier and simpler alternative to determine quercetin, with detection limits of 0.2 mM. The careful selection of the working conditions also made possible the detection of submicromolar levels of quercetin in the presence of excess of rutin. The proposed methodology was successfully used to quantify querecetin in onion samples.