Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination
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 °C) were tested as modifiers. The resu...
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| Format: | Article |
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MDPI AG
2020-12-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/14/1/37 |
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| author | Mayra K. S. Monteiro Djalma R. Da Silva Marco A. Quiroz Vítor J. P. Vilar Carlos A. Martínez-Huitle Elisama V. Dos Santos |
| author_facet | Mayra K. S. Monteiro Djalma R. Da Silva Marco A. Quiroz Vítor J. P. Vilar Carlos A. Martínez-Huitle Elisama V. Dos Santos |
| author_sort | Mayra K. S. Monteiro |
| collection | DOAJ |
| description | 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 °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 µM), with R<sup>2</sup> of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM 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. |
| first_indexed | 2024-03-10T13:48:34Z |
| format | Article |
| id | doaj.art-9d13a7eb53ef4b138926d1981e88b904 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T13:48:34Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-9d13a7eb53ef4b138926d1981e88b9042023-11-21T02:23:07ZengMDPI AGMaterials1996-19442020-12-011413710.3390/ma14010037Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine DeterminationMayra K. S. Monteiro0Djalma R. Da Silva1Marco A. Quiroz2Vítor J. P. Vilar3Carlos A. Martínez-Huitle4Elisama V. Dos Santos5Laboratório de Eletroquímica Ambiental e Aplicada, Universidade Federal do Rio Grande do Norte, Lagoa Nova 59.072-900, BrazilLaboratório de Eletroquímica Ambiental e Aplicada, Universidade Federal do Rio Grande do Norte, Lagoa Nova 59.072-900, BrazilLaboratório de Eletroquímica Ambiental e Aplicada, Universidade Federal do Rio Grande do Norte, Lagoa Nova 59.072-900, BrazilLaboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM), Chemical Engineering Department, Faculty of Engineering, University of Porto, 4200-465 Porto, PortugalLaboratório de Eletroquímica Ambiental e Aplicada, Universidade Federal do Rio Grande do Norte, Lagoa Nova 59.072-900, BrazilLaboratório de Eletroquímica Ambiental e Aplicada, Universidade Federal do Rio Grande do Norte, Lagoa Nova 59.072-900, BrazilThis 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 °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 µM), with R<sup>2</sup> of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM 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.https://www.mdpi.com/1996-1944/14/1/37graphitecorkelectrochemical sensorcaffeinemodified electrode |
| spellingShingle | Mayra K. S. Monteiro Djalma R. Da Silva Marco A. Quiroz Vítor J. P. Vilar Carlos A. Martínez-Huitle Elisama V. Dos Santos Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination Materials graphite cork electrochemical sensor caffeine modified electrode |
| title | Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination |
| title_full | Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination |
| title_fullStr | Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination |
| title_full_unstemmed | Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination |
| title_short | Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination |
| title_sort | applicability of cork as novel modifiers to develop electrochemical sensor for caffeine determination |
| topic | graphite cork electrochemical sensor caffeine modified electrode |
| url | https://www.mdpi.com/1996-1944/14/1/37 |
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