Determination of Quercetin by a Siloxane-Polyester/Poly-L-Lysine Nanocomposite Modified Glassy Carbon Electrode

Author(s)

de Castro Viana Pereira, Elaine Renata ^[1] ; Bessegato, Guilherme Garcia ^[1] ; Yamanaka, Hideko ^[1] ; Boldrin Zanoni, Maria Valnice ^[1]

Affiliation

^[1] Univ Estadual Paulista, UNESP, Inst Chem, Dept Analyt Chem, BR-14800060 Araraquara, SP - Brazil

• Document type: Journal article
• Source: Analytical Letters; v. 49, n. 9, p. 1398-1411, 2016.
• Web of Science Citations: 4

Abstract

Poly-L-lysine incorporated in the nanocavities of polysiloxane-poly(propylene) oxide is reported as an electrochemical sensor for quercetin. A glassy carbon electrode coated by poly-L-lysine/polysiloxane-poly(propylene) oxide accumulated quercetin through hydrogen bonding in pH 2 ethanol/Britton-Robinson buffer. The catecol oxidation was monitored at 0.45V as a reversible two electron peak. The voltammetric response using the film electrode was 80% higher compared to a bare electrode. Square wave voltammetry was employed using an accumulation time of 8min and a linear relationship was obtained for concentrations of quercetin from 1.0x10(-8)mol L-1 to 1.0x10(-6)mol L-1. The limit of detection was 2.76 +/- 0.5x10(-9)mol L-1. The method was employed to determine quercetin in green tea, but did not show selectivity to catechin, which was oxidized at a similar potential. The measurements were validated by high-performance liquid chromatography. (AU)

• FAPESP's process: 12/18357-0 - Study of photoeletrocatalytic degradation of cosmetic dyes with TiO2 nanotube electrodes undoped and doped Sb2S3
• Grantee: Guilherme Garcia Bessegato
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 08/10449-7 - Assessment of occurrence, toxicity/genotoxicity and degradation processes of dyes in effluents and surface water
• Grantee: Maria Valnice Boldrin
• Support Opportunities: Research Projects - Thematic Grants