Double-Walled Carbon Nanotubes Functionalized with Allium sativum (Garlic Extract): Analytical Applications for Pb(II) Electrochemical Sensing.

FABRIZIO PERRACHIONE; PABLO R. DALMASSO*; FABIANA A. GUTIERREZ*, GUSTAVO A. RIVAS*

MICROCHEMICAL JOURNAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2021 vol. 160

0026-265X

n the present work we report an electrochemical sensor for the selective and sensitive quantification of Pb(II) based the use of glassy carbon electrodes (GCEs) modified with double-walled carbon nanotubes (DWCNTs) non-covalently functionalized with Allium sativum extract (garlic extract, Gar), (GCE/DWCNTsGar). FTIR, UV-vis spectroscopy, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry were used to characterize the DWCNTs-Gar dispersion. Pb(II) was accumulated at GCE/DWCNTs-Gar at open circuit potential for 20.0 min via complex formation with the organo-sulfur compounds residues present in the Gar extract, followed by the reduction at -0.900 V, and final reoxidation by voltammetric stripping. The sensitivity was (72 ± 8) x 10-3 uA ug−1 L, the reproducibility was 11.1% using five different dispersions, and the detection limit was 1.5 ug L−1. The quantification of Pb(II) was highly selective even in the presence of other cations of ecotoxicological releva