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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Evaluation of a Graphite-Polyurethane Composite Electrode Modified with Copper Nanoparticles as an Amperometric Flow Detector in a Wall-Jet System for the Determination of Cysteine

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Author(s):
Mattioli, Isabela A. [1] ; Schildt, Leticia F. L. [1] ; Cervini, Priscila [1] ; Saciloto, Thalita R. [1] ; Cavalheiro, Eder T. G. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Quim Sao Carlos, Av Trabalhador Sao Carlene 400, BR-13566590 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Journal of the Brazilian Chemical Society; v. 31, n. 2, p. 370-380, FEB 2020.
Web of Science Citations: 0
Abstract

A graphite-polyurethane composite electrode (GPUE) was modified by electrodeposition of copper nanoparticles (CuNP) followed by electrochemical treatment in NaOH (GPUE-CuNP), in order to prepare an amperometric sensor for the determination of cysteine (Cys). Cyclic votammograms of Cys solutions at GPUE-CuNP allowed the description of a sequence of electrochemical reactions involving Cys oxidation and Cu/Cu+ equilibrium, generating a stable Cys-Cu+ complex. The presence of these nanoparticles was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) data. Hence, the developed device was then used as a Cys amperometric flow detector in a wall-jet system, after evaluation of flow injection parameters in an undescribed approach. In this system, a limit of detection (LOD) of 4.24 µmol L-1 was obtained with an analytical frequency of 36 determinations h-1. Intra-day and inter-day reproducibility and repeatability of the modified surface was evaluated. Then the GPUE-CuNP performance was investigated in the determination of Cys content in food supplements. Interference tests were carried out with pyridoxine, ascorbic acid, tryptophan and SO4 2- ions. The main interference was attributed to the interaction of some of these substances with copper oxides. (AU)

FAPESP's process: 18/11071-0 - Development and application of disposable screen-printed composite electrodes based on metallic nanoparticles and graphite-polyurethane
Grantee:Isabela Alteia Mattioli
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
FAPESP's process: 17/04211-7 - Development of inks based on metalic nanoparticles and polymers for the preparation of conventional and printed electrodes
Grantee:Éder Tadeu Gomes Cavalheiro
Support Opportunities: Regular Research Grants