Expanded graphite modified with intercalated montmorillonite for the electrochemical determination of catechol

Selective determination of cuprous ion in copper dissolving solution based on bathocuproine-modified expanded graphite electrode

The presence of cuprous ions in the copper-dissolving solution significantly affects the microstructure of copper plated surface. Fewer quantitative analyses of cuprous ions in the copper foil productive process had rarely been involved so far. In the present work, a novel electrochemical sensor of the bathocuproine (BCP) modified expanded graphite (EG) electrode was developed for the selective determination of cuprous ions. EG has a large surface area, good adsorption, and excellent electrochemical performance which remarkably promoted analytical sensitivity. Meanwhile, the selective determination of the BCP-EG electrode for cuprous ions in the coexistence of ten thousand times of copper ions have been achieved on the benefit of the special coordination of BCP to cuprous ions. In the coexistence of 50 g/L copper ions, the analytical performance of the BCP-EG electrode for the determination of cuprous ions had been examined. The results represented a wide detection range of cuprous ions in the range of 1.0 μg/L-5.0 mg/L, with a low detection limit of 0.18 μg/L (S/N = 3) and the BCP-EG electrode has great selectivity to cuprous ions in presence of various interferences. The analytical selectively for cuprous ions supported by the proposed electrode would be a potential analytical tool for quality improvement in electrolytic copper foil manufacturing.

A mechanothermal approach for the synthesis of Fe3O4 nanoparticles as dopant on mesoporous TiO2 for electrochemical determination of catechol

The subject of water contamination and how it gets defiled to the society and humans is confabulating from the past decades. Phenolic compounds widely exist in the water sources and it is emergent to determine the toxicity in natural and drinking water, because it is hazardous to the humans. Among these compounds, catechol has sought a strong concern because of its rapid occurrence in nature and its potential toxicity to humans. The present work aims to develop an effective electrochemical sensing of catechol using mesoporous structure of Fe₃O₄-TiO₂ decorated on glassy carbon (GC) electrode. The creation of pure TiO₂ using the sol-gel technique was the first step in the synthesis protocol for binary nanocomposite, which was then followed by the loading of Fe₃O₄ nanoparticles on the surface of TiO₂ using the thermal decomposition method. The resultant Fe₃O₄-TiO₂ based nanocomposite exhibited mesoporous structure and the cavities were occupied with highly active magnetite nanoparticles (Fe₃O₄) with high specific surface area (90.63 m²/g). When compared to pure TiO₂, catechol showed a more prominent electrochemical response for Fe₃O₄-TiO₂, with a significant increase in anodic peak current at a lower oxidation potential (0.387 V) with a detection limit of 45 μM. Therefore, the prepared magnetite binary nanocomposite can serve as an efficient electroactive material for sensing of catechol, which could also act as a promising electrocatalyst for various electrocatalytic applications.

Recent Prospects of Carbonaceous Nanomaterials-Based Laccase Biosensor for Electrochemical Detection of Phenolic Compounds

Phenolic compounds (PhCs) are ubiquitously distributed phytochemicals found in many plants, body fluids, food items, medicines, pesticides, dyes, etc. Many PhCs are priority pollutants that are highly toxic, teratogenic, and carcinogenic. Some of these are present in body fluids and affect metabolism, while others possess numerous bioactive properties such as retaining antioxidant and antimicrobial activity in plants and food products. Therefore, there is an urgency for developing an effective, rapid, sensitive, and reliable tool for the analysis of these PhCs to address their environmental and health concern. In this context, carbonaceous nanomaterials have emerged as a promising material for the fabrication of electrochemical biosensors as they provide remarkable characteristics such as lightweight, high surface: volume, excellent conductivity, extraordinary tensile strength, and biocompatibility. This review outlines the current status of the applications of carbonaceous nanomaterials (CNTs, graphene, etc.) based enzymatic electrochemical biosensors for the detection of PhCs. Efforts have also been made to discuss the mechanism of action of the laccase enzyme for the detection of PhCs. The limitations, advanced emerging carbon-based material, current state of artificial intelligence in PhCs detection, and future scopes have also been summarized.

Simultaneous detection of acetaminophen, catechol and hydroquinone using a graphene-assisted electrochemical sensor

Simple, rapid and sensitive analysis of drug-derived pollutants is critically valuable for environmental monitoring. Here, taking acetaminophen, hydroquinone and catechol as a study example, a sensor based on an ITO/APTES/r-GO@Au electrode was developed for separate and simultaneous determination of phenolic pollutants. ITO electrodes that are modified with 3-aminopropyltriethoxysilane (APTES), graphene (GO) and Au nanoparticles (Au NPs) can significantly enhance the electronic transport of phenolic pollutants at the electrode surface. The redox mechanisms of phenolic pollutants include the electron transfer with the enhancement of r-GO@Au. The modified ITO electrode exhibits excellent electrical properties to phenolic pollutants and a good linear relationship between ECL intensity and the concentration of phenolic pollutants, with a limit of detection of 0.82, 1.41 and 1.95 μM, respectively. The separate and simultaneous determination of AP, CC and HQ is feasible with the ITO/APTES/r-GO@Au electrode. The sensor shows great promise as a low-lost, sensitive, and rapid method for simultaneous determination of drug-derived pollutants.

Simple, rapid and sensitive analysis of drug-derived pollutants is critically valuable for environmental monitoring.