Graphene Paste Electrode: Analytical Applications for the Quantification of Dopamine, Phenolic Compounds and Ethanol

Abstract

This work reports the analytical applications of a graphene paste electrode (GrPE) for the quantification of dopamine, ethanol and phenolic compounds. Dopamine was detected by differential pulse voltammetry‐adsorptive stripping with medium exchange at submicromolar levels even in the presence of high excess of ascorbic acid and serotonin. The electrocatalytic activity of graphene towards the oxidation of NADH and the reduction of quinones allowed the sensitive amperometric determination of ethanol and phenols using GrPE modified with alcohol dehydrogenase/NAD+ or polyphenol oxidase, respectively, with successful applications in real samples like alcoholic beverages and tea.

AuNP/Cu-TCPP(Fe) metal–organic framework nanofilm: a paper-based electrochemical sensor for non-invasive detection of lactate in sweat

“…12 However, it is difficult to make measurements on bare electrodes due to serious limitations such as the electrode structure and similar redox potentials. 13,14 For solving these limitations, scientists have developed a variety of materials to modify the working electrode, among which nanomaterials show broad application prospects due to their unique properties.…”

Artificial Neural Networks for the Resolution of Dopamine and Serotonin Complex Mixtures Using a Graphene‐Modified Carbon Electrode

“…There are different electroanalytical methods for the detection of neurotransmitters in complex mixtures in literature; among these the most common strategies to deal with the overlapping of the signals is the use of biocomposites with or without nanomaterials to improve sensor performance. Although papers about the selective detection of DA, 5‐HT, AA and UA have often been reported, they have mostly tackled the issue as a sample with one important analyte and 2 or 3 interfering compounds, what makes easier its quantification.…”

Multi‐walled Carbon Nanotubes Non‐covalently Functionalized with Polyarginine: A New Alternative for the Construction of Reagentless NAD+/Dehydrogenase‐based Ethanol Biosensor

“…Therefore, new strategies are required for the construction of reagentless dehydrogenase‐based electrochemical biosensors in which both, the enzyme and NAD + , are effectively immobilized onto the electrode in such a way that the cofactor has easy acces to the enzyme. For example, NAD + cofactor has been entrapped in graphene or carbon nanotube paste electrodes , immobilized in sol‐gel composite thin films , covalently immobilized on chitosan chains for the modification of carbon nanotubes , or non‐covalently attached onto carbon nantubes by π‐π stacking interaction . Another limitation in the use of NAD + ‐based‐dehydrogenases is the requirement of elevated overvoltages for the electrooxidation of NADH (enzymatically generated from NAD + ) and the passivation of the electrodes surfaces produced by the NADH oxidation products, that affects the selectivity, reproducibility and stability of the electrochemical platforms .…”