Novel cork-graphite electrochemical sensor for voltammetric determination of caffeine

Monteiro, Mayra Kerolly Sales; Paiva, Suelya S.M.; Silva, Djalma Ribeiro da; Vilar, Vítor J.P.; Martínez‐Huitle, Carlos A.; Santos, Elisama Vieira dos

doi:10.1016/j.jelechem.2019.03.030

Cited by 31 publications

(22 citation statements)

References 35 publications

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“…Due to their inherent specificity, rapid measurement procedures, high accuracy, high sensitivity and simplicity of preparation, these measuring devices allow monitoring of different species in a satisfactory way. The low cost and the absence of toxic solvents, necessary in other techniques such as chromatography and spectrophotometry, should also be mentioned [ 18 , 19 ].…”

Section: Introductionmentioning

confidence: 99%

“…Recently, raw cork materials have been proposed as novel modifiers for developing electrochemical sensors [ 19 , 23 , 24 ] because their physical and chemical properties favor interactions with target species to be detected or/and quantified. Cork is obtained from the outer bark of the Quercus suber L. oak [ 25 ] and its composition consists of 33–50% suberin, 13–29% lignin, 6–26% cellulose and hemicellulose polysaccharides and 11–24% of tannis and waxes [ 26 , 27 ].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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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 R2 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.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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“…of its original activity for CAF, indicating the electrode was very stable. Graphene oxide-Nafion/GCE 2.0 0.20 [22] MWCNT-Nafion/GCE 4.1 0.51 [43] Nafion/GCE 1.0 0.79 [23] Nafion/MWCNT/GCE 2.0 0.23 [21] Attapulgite/Nafion/GCE 1.5 0.045 [26] 4-Cu II TAPc/SAM/GCE 4.0 0.0304 [44] ZnO/MWCNT/GCE 1.0 0.0097 [45] Pt-GR/GCE / 0.1129 [46] GORG/CPE/SDS 1.0 0.153 [47] GrRAC-70% / 2.94 [48] NCOM/CPE/SDS 0.75 0.016 [49] 3D-printed cell-on-a-chip / 2.84 [50] GCE / 20 [51] Nafion/PDDA-MWCNT/GCE 1.5 0.05 [52] Fullerene/MWCNT/Naf/GCE…”

Section: Interference Study Repeatability and Stability Of The Electmentioning

confidence: 99%

Fullerene/MWCNT/Nafion Modified Glassy Carbon Electrode for the Electrochemical Determination of Caffeine

Tajeu¹,

Dongmo²,

Tonlé³

2020

AJAC

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Herein, a convenient method based on a fullerene/multiwalled carbon nanotube/Nafion modified glassy carbon electrode (fullerene/MWCNT/Naf/GCE) for the electrochemical determination of caffeine (CAF) is reported. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to study ionic exchange properties and conductivity the proposed electrode using [Fe(CN) 6 ] 3−/4− redox couple. Caffeine gave an irreversible oxidation peak around +1.33 V (vs. Ag/AgCl reference electrode) in HClO 4 (pH 1). The linear dependence of the peak current with the square root of the scan rate showed that the electron transfer process is controlled by diffusion. After optimization of key analytical parameters involved in differential pulse voltammetry (DPV), the oxidation peak current varied linearly with CAF concentration in the range of 10 to 1000 µM. A detection limit of 7.289 × 10 −8 M (S/N = 3) was found. Kinetic and chronocoulometric studies were also performed to characterize the diffusion of CAF. The developed electrode exhibited good stability and was easily regenerated. The influence of some potential interfering compounds such as dopamine, uric acid, glucose and sulfite ions on the anodic peak current of CAF was also examined. The proposed method was successfully employed in the determination of CAF in some commercial drugs.

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Section: Corkmentioning

confidence: 99%

“…Meanwhile, about 40% of the total acid groups correspond to strong acids and 50% correspond to the overall phenolic OH groups. Therefore, its formidable characteristics are promising resources with potential application on adsorption technologies [18]. Herewith cork is a natural, cheap, renewable, fully sustainable, and biodegradable raw material with a very relevant advantage over other carbonaceous materials to be explored as a sorbent in many applications [19].Since it was first described as an adsorbent in 2005, [20] its use in environmental applications for the removal of a variety of organic and inorganic pollutants has gained considerable attention, and a large number of research articles, as well as reviews, covering this approach have been published [17,[21][22][23][24][25][26].…”

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confidence: 99%

Returning to Nature for the Design of Sorptive Phases in Solid-Phase Microextraction

et al. 2019

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Green analytical chemistry principles aim to minimize the negative impact of analytical procedures in the environment, which can be considered both at close (to ensure the safety of the analysts) and global (to conserve our natural resources) levels. These principles suggest, among other guidelines, the reduction/minimization of the sample treatment and the use of renewable sources when possible. The first aspect is largely fulfilled by microextraction, which is considered to be among the greenest sample treatment techniques. The second consideration is attainable if natural products are used as raw materials for the preparation of new extraction phases. This strategy is in line with the change in our production system, which is being gradually moved from a linear model (take-make-dispose) to a circular one (including reusing and recycling as key terms). This article reviews the potential of natural products as sorbents in extraction and microextraction techniques from the synergic perspectives of two research groups working on the topic. The article covers the use of unmodified natural materials and the modified ones (although the latter has a less green character) to draw a general picture of the usefulness of the materials.Separations 2020, 7, 2 2 of 22 principle identifies one of the trends of current research in analytical sciences, it is difficult to be applied when complex samples containing the analytes at very low concentrations are processed. In such scenarios, the simplification of the sample treatment and the reduction of the sources applied (reagents, energy) can be a more practical objective, at least currently. Microextraction techniques fulfill the latter criteria [8], and they are considered among the greenest sample treatment techniques [9].Microextraction techniques have evolved in the last decade following some key trends. Among them, the development of new extraction phases can be highlighted, considering the context of this review article. In this evolution, the tenth (use of renewable resources) and eleventh (replace or remove toxic reagents) principles of GAC are especially relevant [7]. In the liquid microextraction context, environmentally friendly solvents [10,11] such as CyreneTM [12] and deep eutectic solvents [13] are clear examples of this progress.The paradigm of our production system, which up to now has been based on a linear "take-make-dispose" model, is progressively changed to a circular model [14] where reusing, repairing, refurbishing, and recycling appear as key terms. The use of surpluses of natural products as raw materials for the preparation of new sorbents is an interesting contribution of analytical chemistry for changing the production model. This review article, which combines the vision of two research groups working in the topic, tries to draw the general picture of the potential of natural products for the synthesis of new sorptive phases in solid phase extraction and solid phase microextraction. The article will cover strategies with different green characterist...

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Novel cork-graphite electrochemical sensor for voltammetric determination of caffeine

Cited by 31 publications

References 35 publications

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

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

Fullerene/MWCNT/Nafion Modified Glassy Carbon Electrode for the Electrochemical Determination of Caffeine

Returning to Nature for the Design of Sorptive Phases in Solid-Phase Microextraction

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