Carbon paper as a promising sensing material: Characterization and electroanalysis of ketoprofen in wastewater and fish

• Published in: Talanta (Oxford) Vol. 226; p. 122111
• Main Authors: Torrinha, Álvaro, Martins, Marco, Tavares, Miguel, Delerue-Matos, Cristina, Morais, Simone
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-05-2021
• Subjects: Carbon; Carbon paper; Contaminants of emerging concern; Electrodes; Environmental analysis; Fish; Ketoprofen; Reproducibility of Results; Waste Water; Wastewater; Fish; Contaminants of emerging concern; Environmental analysis; Wastewater; Carbon paper; Ketoprofen
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2021.122111

In the present work, the exceptional electrochemical properties of carbon paper were characterized and explored in the development of a sensor for the anti-inflammatory drug, ketoprofen. An initial electrochemical characterization of the carbon paper with a redox indicator revealed much higher voltammetric peaks in comparison with other carbon-based electrodes, namely, screen-printed carbon electrode, boron-doped diamond electrode, glassy carbon electrode, pyrolytic graphite electrode, and pencil graphite electrode, predicting a good sensing performance. Ketoprofen showed a pronounced cathodic peak around −1.1 V vs Ag/AgCl (KCl, 3 M) at pH 5 in Britton-Robinson buffer, presenting a diffusion-controlled process. An optimized differential pulse voltammetry procedure was employed for ketoprofen determination achieving a limit of detection of 0.11 ± 0.01 μM, a linearity up to 6.02 μM, and a high sensitivity of 24 ± 4 or 35 ± 3 μA μM−1 cm−2 (depending on the calibration range: 0.088–1.96 μM or 1.96–6.02 μM, respectively) with acceptable (6–15% relative standard deviation) reproducibility and repeatability considering the challenging conditions of its detection in aqueous solutions. The sensor revealed to be highly selective in the presence of common interferents and other widely consumed anti-inflammatory drugs. Moreover, the developed sensor reached good accuracy in wastewater and fish samples with recoveries varying from 82.3 ± 4.4 to 88.6 ± 4.5%.
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•An unmodified carbon paper was efficiently used as sensor for ketoprofen analysis.•Higher voltammetric peaks were obtained compared to other carbon-based electrodes.•The ketoprofen sensor achieved high sensitivity (35 μA μM cm−2) and low LOD (0.11 μM).•Recoveries of 82.3–88.6% were obtained for complex samples of wastewater and fish.•Carbon paper constitutes a promising sensor for in-situ environmental analysis.