Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination

Autor(es)

Monteiro, Mayra K. S. ^[1] ; Da Silva, Djalma R. ^[1] ; Quiroz, Marco A. ^{[1, 2]} ; Vilar, Vitor J. P. ^[3] ; Martinez-Huitle, Carlos A. ^{[4, 1]} ; Dos Santos, Elisama V. ^{[4, 1]}

Afiliação do(s) autor(es)

^[1] Univ Fed Rio Grande do Norte, Lab Eletroquim Ambiental & Aplicada, BR-59072900 Lagoa Nova - Brazil

^[2] Univ Americas Puebla, Grp Invest Energia & Ambiente, Cholula 72820 - Mexico

^[3] Univ Porto, Fac Engn, Chem Engn Dept, Lab Separat & React Engn, Lab Catalysis & Mat, P-4200465 Porto - Portugal

^[4] Unesp, Natl Inst Alternat Technol Detect Toxicol Evaluat, Inst Chem, POB 355, BR-14800900 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS; v. 14, n. 1 JAN 2021.
• Citações Web of Science: 0

Resumo

This study aims to investigate the applicability of a hybrid electrochemical sensor composed of cork and graphite (Gr) for detecting caffeine in aqueous solutions. Raw cork (RAC) and regranulated cork (RGC, obtained by thermal treatment of RAC with steam at 380 degrees C) were tested as modifiers. The results clearly showed that the cork-graphite sensors, GrRAC and GrRGC, exhibited a linear response over a wide range of caffeine concentration (5-1000 mu M), with R-2 of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 mu M for GrRAC and GrRGC, suggest greater sensitivity and reproducibility than the unmodified conventional graphite sensor. The low-cost cork-graphite sensors were successfully applied in the determination of caffeine in soft drinks and pharmaceutical formulations, presenting well-defined current signals when analyzing real samples. When comparing electrochemical determinations and high performance liquid chromatography measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of these sensors to determine caffeine in different samples. (AU)

• Processo FAPESP: 14/50945-4 - INCT 2014: Instituto Nacional de Tecnologias Alternativas para Detecção, Avaliação Toxicológica e Remoção de Micropoluentes e Radioativos
• Beneficiário: Maria Valnice Boldrin
• Modalidade de apoio: Auxílio à Pesquisa - Temático