Copper phthalocyanine conjugated graphitic carbon nitride nanosheets as an efficient electrocatalyst for simultaneous detection of natural antioxidants

Metal-free electrocatalytic nanocomposites of poly azovan blue-decorated graphitic carbon nitride for simultaneously sensing paracetamol and 4-aminophenol

Excessive consumption of paracetamol (PA) and 4-aminophenol (4-AP) can have harmful effects on the human body. This study developed a novel electroanalytical technique that utilizes the nanocomposites of poly azovan blue (PAB)-decorated graphitic carbon nitride (g-C3N4), deposited onto a screen-printed carbon electrode (SPCE), for the concurrent sensing of PA and 4-AP. The fabricated g-C3N4@PAB/SPCE exhibited exceptional synergistic effects, such as a high active electrochemical surface area and excellent electron transfer properties. The electrochemical behavior of g-C3N4@PAB/SPCE for simultaneous PA and 4-AP sensing was evaluated in the linear dynamic ranges of 0.08-75 and 0.05-90 μM, with the detection limits (S/N = 3) of 0.011 and 0.016 μM and sensitivities of 2.974 and 2.857 μA/μM/cm-2 for PA and 4-AP, respectively. Additionally, g-C3N4@PAB/SPCE showed long-term stability, high reproducibility (RSD = 2.17%, n = 4), and superior anti-interference capabilities. Finally, when g-C3N4@PAB/SPCE was tested for simultaneously sensing both PA and 4-AP in tap water and artificial urine models, it exhibited satisfactory recoveries, demonstrating its potential use for various industrial and clinical applications.

Emerging Trends in nanostructured materials-coated screen printed electrodes for the electrochemical detection of hazardous heavy metals in environmental matrices

Heavy metal ions (HMIs) have become a significant contaminant in recent years. The increase in heavy metal pollution is a serious situation, requiring progressively robust, fast sensing, highly sensitive, and suitable techniques for heavy metal detection. Compared to other classical analytical methods, electroanalytical techniques, especially stripping voltammetric techniques with modified screen-printed electrodes (SPEs), have several advantages, such as fast sensing, great sensitivity, specificity, and long-time stability. Therefore, these techniques are more suitable for HMI detection. In this review, the nanostructured materials used to coat SPEs for the electrochemical determination of HMI are summarized. Additionally, the electrode fabrication method, modification steps, and electroanalytical study of these materials are systematically discussed. Hence, this review will support the researchers in precisely evaluating the electrochemical HMIs detection through highly sensitive stripping voltammetric techniques using SPE modified with nanostructured carbon and their allotropes, metal, metal oxides and their nanocomposites as sensor materials. Moreover, modified electrodes real time detection of HMIs in different food and environmental samples were briefly discussed.

Electrochemical Sensing of Gallic Acid in Beverages Using a 3D Bio-Nanocomposite Based on Carbon Nanotubes/Spongin-Atacamite

Gallic acid (GA) is one of the most important polyphenols, being widely used in the food, cosmetic, and pharmaceutical industries due to its biological effects such as antioxidant, antibacterial, anticancer, antiviral, anti-inflammatory, and cardioprotective properties. Hence, simple, fast, and sensitive determination of GA is of particular importance. Considering the fact that GA is an electroactive compound, electrochemical sensors offer great potential for GA quantitation due to their fast response time, high sensitivity, and ease of use. A simple, fast, and sensitive GA sensor was fabricated on the basis of a high-performance bio-nanocomposite using spongin as a natural 3D polymer, atacamite, and multi-walled carbon nanotubes (MWCNTs). The developed sensor showed an excellent response toward GA oxidation with remarkable electrochemical features due to the synergistic effects of 3D porous spongin and MWCNTs, which provide a large surface area and enhance the electrocatalytic activity of atacamite. At optimal conditions by differential pulse voltammetry (DPV), a good linear relationship was obtained between peak currents and GA concentrations in a wild linear range of 500 nM to 1 mM. Subsequently, the proposed sensor was used to detect GA in red wine as well as in green and black tea, confirming its great potential as a reliable alternative to conventional methods for GA determination.

A novel electrochemical sensor based on an Fe–N–C/AuNP nanohybrid for rapid and sensitive gallic acid detection

An Fe–N–C/AuNP nanohybrid was combined with a glassy carbon electrode to construct a novel electrochemical sensor for rapid detection of gallic acid (GA). The sensor exhibited excellent performance to detect GA with a wide linear response range and low detection limit.

Fast Analysis of Caffeic Acid-Related Molecules in Instant Coffee by Reusable Sonogel-Carbon Electrodes

Reusable Sonogel-Carbon electrodes containing carbon black (SNGC-CB) have been used for the electrochemical analysis of caffeic acid (CA) in real matrices. Measurements were firstly performed in standard solutions, in which SNGC-CB electrodes allowed the electrochemical determination of CA with high sensitivity and low limit of detection, equal to 0.76 μM. The presence of CB nanostructures in the formulation led to improved performances with respect to pristine SNGC electrodes. Then, measurements were performed in four instant coffees of different brands. A comparison between the results obtained by electrochemical, chromatographic and spectroscopic methods showed that SBGC-CB electrodes represent a simple and economic tool for the rapid assessment of caffeic acid-related molecules in instant coffees.