A novel electrochemical method for detecting synthetic cannabinoids in e-cigarette and biological samples using a lab-made electrode.

L-A9 is one of the important short peptides having biomedical applications in relation to its affinity towards HER2 receptors. The peptide has been synthesised using manual solid phase synthesis protocol and the redox property has been investigated using the voltammetric techniques. The oxidation peak of the peptide has shown strong pH dependency, revealed the 1 e and 2 proton transfer process. Electroanalytical method is developed with limit of detection of 1.17 × 10−7 M. The modulation of the redox property has been monitored to investigate the binding of the peptide with dsDNA, with binding constant of 1.8 × 10⁵ M− 1. Spectroscopic measurements of the peptide revealed the pH dependent electronic transition and the binding constant with dsDNA of 1.4 × 104 M− 1. The needle like assembly of L-A9 peptide has been indicated from the SEM measurements with coil kind of morphology of dsDNA has been observed when the L-A9 peptide and dsDNA interacted with each other. The electrochemical and spectroscopic investigations indicated that the acidic functional groups of L-A9 interacts with the major groove of dsDNA through the modifications of 3 hydrogen bonds between the strands, whereas the basic functional groups of L-A9 binds externally with dsDNA by formation of bonds with O atoms of the phosphodiester groups, which has been supported from the molecular docking investigations.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-30000-w.

Actinide electrochemistry is a scientifically rich field of study with numerous oxidation states for each element. Electrochemical applications include aqueous and molten salts that commonly focus on separations and detection, utilizing chemical redox mediation, electrochemical engineering, and electroanalytical method development. An overview and history of actinide electrochemistry will be reviewed.

Novel porous titanium nitride microelectrode for selective detection of Zn2+ ion by electroanalytical method

In this study, a carbon graphite-clay paste electrode (CPEA) was proposed to study the electrochemical behavior of drugs such as azithromycin (AZI) and hydroxychloroquine (HYC). The electrochemical analysis was carried out by cyclic voltammetry (VC) in the potential range [-0.03; 0.35 V], in a phosphate buffer solution (0.1 M; pH = 6.4). It is in this logic that before the elaboration of the carbon graphite-clay composite, the clay powder was prepared and its structural and textural properties were examined by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM). The results indicate that the electrode was effectively modified. The electrode was then subjected to electroanalysis at the same concentrations (3 mM) for individual and combined AZI, HYC, and AZI+HYC. However, in the presence of analyte, the phenomena are irreversible, with oxidation phenomena dominating. The electroactivity of the drugs used concerns the hydroxyl groups, observed around 0.18 V. Furthermore, an interaction study in the analytical application was conducted and it was found that the electroanalytical method used can be well adopted for the simultaneous electrochemical detection of HYC and AZI.

Utilization of a simple and fast electroanalytical method with an unmodified boron-doped diamond electrode for taxifolin sensing in food supplement samples

Innovation in venlafaxine detection: Development and application of electroanalytical method using a boron-doped diamond electrode and performance comparison with UHPLC-MS/MS.

Objective: In this study, a low-cost, sensitive and practical electroanalytical method was developed and validated for the determination of Linagliptin (LNG), a therapeutic agent used in the treatment of Diabetes Mellitus, one of the most common chronic diseases worldwide, characterized by high blood glucose levels and directly affecting millions of people. Material and Method: Electroanalytical studies were completed using screen-printed carbon electrodes in pH: 8 Britton - Robinson buffer solution. Mechanistic studies were carried out by cyclic voltammetry technique. Adsorptive stripping differential pulse voltammetry technique was used for the electrochemical determination of LNG. Result and Discussion: The developed method exhibited linearity in the range of 0.1 - 7.5 µM and the limit of detection value was calculated as 37 nM. The developed method was applied for the determination of LNG from urine and a recovery value of 100.02% was obtained.

Simultaneous voltammetric determination of 3-methyladenine and adenine at disposable screen-printed carbon electrode.

In this study, a sensitive, fast, economical, and practical voltammetric method was developed for analysing molnupiravir (MLP), an antiviral drug extensively used during the COVID-19 pandemic, without the need for modifying the glassy carbon (GC) electrode surface. During the electroanalysis, an oxidation peak for MLP was detected at 0.72555 V on the GC electrode. The method exhibited linearity across a concentration range of 1 - 250 µM for MLP with 0.33 µM of detection limit. Furthermore, with a 99.81% recovery from its pharmaceutical form, the method's effectiveness was validated. These results strongly indicate that this method is suitable for routine quality control of molnupiravir and may serve as a model for analysing other antiviral drugs.

This study investigates the electrochemical behavior of L-cysteine using cyclic voltammetry (CV) on a glassy carbon electrode (GCE) in aphosphate buffer solution (pH 8.0). Cysteine, a biologically significant thiol-containing amino acid, exhibits an irreversible oxidation peakcorresponding to the electrooxidation of its -SH group, following a diffusion-controlled mechanism. The influence of scan rate (10–70 mV/s)and pH (4.0–9.0) on the redox process was systematically examined, revealing a proton-coupled electron transfer (PCET) mechanism. Themethod was validated as per ICH guidelines, demonstrating excellent linearity (10–50 x10-3 M, R² = 0.9752), precision (%RSD < 1.12%),accuracy (recovery 98.64–103.06%), and sensitivity (LoD = 0.192 x10-2 M, LoQ = 0.582 x10-2 M). Robustness studies confirmed methodstability under slight pH variations. These findings establish CV as a rapid, sensitive, and cost-effective alternative for cysteine quantificationin biochemical and nutritional analysis.

Development of an Electroanalytical Method for the Simultaneous Determination of Trace Elements in Stingless Bee Honey Samples Using a Boron-Doped Diamond Electrode

SUMMARYResearch backgroundNowadays, there is still no portable electroanalytical device suitable for the monitoring concentration of chlorophenols in technologically used water, especially in the brewing industry. This problem could be solved by developing an electroanalytical screening method based on chlorophenol anodic oxidation.Experimental approachThe electrochemical behaviour of the target chlorophenols was investigated to find the optimum working conditions for their selective electrochemical detection in beer.Results and conclusionsElectrochemical oxidation pathways were proposed for each investigated chlorophenol. The sum of all chlorophenols present in the brewing water, expressed as the concentration equivalent of 2,6-dichlorophenol, can be determined electrochemically, so that in future real-time monitoring of chlorophenols in the individual stages of the beer production process will be possible. Moreover, the cathodic reduction of their oxidation products proved to be a suitable electroanalytical tool for the selective detection of their presence in beer.Novelty and scientific contributionThe research shows that an electroanalytical approach could be useful in the control of beer biotechnology to prevent sensory changes caused by the chlorophenols formed.

Abstract An electrochemical sensor for the simultaneous detection of mangiferin (MAN) and neomangiferin (NEO) was developed using CuBTC and GO-COOH through an electroreduction method for the first time. The electrochemical properties of the CuBTC@ErGO-COOH/GCE and the electrochemical behavior of MAN and NEO on this sensor were investigated. Several factors were investigated, including the concentration of CuBTC, pH value, accumulation time and scanning rate using cyclic voltammetry. The electrochemical reaction processes of MAN and NEO on the CuBTC@ErGO-COOH/GCE were inferred. An electroanalytical method was developed for the simultaneous detection of MAN and NEO using linear sweep voltammetry, allowing for precise and sensitive quantification of both compounds. The electrode reaction processes of MAN and NEO on the CuBTC@ErGO-COOH/GCE were both determined to be diffusion-controlled. The linear ranges for MAN and NEO were established from 0.1 ~ 8 μM, with the detection limits of 8.1 nM and 17 nM (S/N=3), respectively. The sensor demonstrated good repeatability, reproducibility, stability and anti-interference ability. Furthermore, it was successfully applied to the simultaneous detection of MAN and NEO in urine and serum samples with satisfactory recovery.

The rapid increase in waste production, driven by the Industrial Revolution, has led to significant environmental challenges, particularly the contamination of soil and water from landfill leachate. This study aims to evaluate the removal of heavy metals (zinc, cadmium, and lead) from landfill leachate through chemical precipitation using the analytical technique of square wave voltammetry by anodic re-dissolution. The study involved sequential stages, starting with adjustments to the electroanalytical method and calibration curve development, followed by precipitation assays with a synthetic metal solution to optimize variables for heavy metal removal. Precipitation experiments were conducted using zinc, cadmium, and lead ions with calcium hydroxide and sodium carbonate, and voltammetric analyses were performed using square wave anodic stripping voltammetry to assess metal concentrations. The study examined the electrochemical behavior of Bi³? using square wave voltammetry, revealing linear relationships between peak current and frequency, indicating reversibility in the reaction. Optimization of parameters such as frequency, step, and pulse amplitude improved the precision and selectivity of the analysis. Bi³? concentration was optimized for maximum electroanalytical response, with a concentration of 1.25 mg L?¹ selected. Deposition time was also optimized, with 300 seconds providing the best results. Metal removal efficiency using precipitating agents (Ca(OH)? and Na?CO?) was analyzed, showing higher efficiency for lead and cadmium with Ca(OH)?. The study highlights the significance of pH and agent concentration in the removal process. This study evaluated the removal of heavy metals (zinc, cadmium, and lead) from landfill leachate using chemical precipitation with calcium hydroxide and sodium carbonate. The process achieved high removal rates, particularly for lead (97.97%). Square wave voltammetry was successfully developed for precise quantification, with statistical validation confirming its reliability for this application.

Hydrogen Sulfide (H₂S) is a biologically active endogenous gas, produced in mammalian tissues, which plays a critical role in several pathophysiological processes, including oncogenesis. This gas-transmitter can exert diametrically opposite effects on neoplastic cell proliferation, depending on the duration and concentration of H₂S exposure. Due to this dual role, antineoplastic drugs, aimed at modulating H₂S levels, are attracting considerable interest in both research and clinical settings. On this basis, H₂S could serve as a diagnostic biomarker, potentially indicating the presence and stage of a tumor in body fluids that can be analyzed by liquid biopsy. In this work, an electrochemical sensor, screen-printed on filter paper, and then modified with a dispersion of Prussian blue, synthesized directly on the paper, was developed in order to detect H₂S in tissue lysates. After the optimization of several experimental parameters, the sensor was analytically characterized in standard solution, achieving a good repeatability and a detection limit of 3μM, and the repeatability of the entire platform appeared to be lower than 10%. The sensor was then applied to determine H₂S in biological samples, including a murine skin lysate, two pharmacologically treated neoplastic murine lysates, and an untreated neoplastic murine lysate, obtaining results in agreement with those observed with the standard methylene blue-based assay for H₂S determination, demonstrating the applicability of the developed electroanalytical method for liquid biopsy. It might represent a significant revolution in cancer diagnosis, and the use of point of care (PoC) platforms is a promising strategy to speed up and simplify operations, providing rapid and on-site analysis. In particular, the possibility of using portable miniaturized sensors allowed to reduce the amount of sample to analyzed: it usually represents an issue of traditional approaches.

OF DIFFERENT MANUFACTURES It was established that spectroscopic and chromatographic methods of analyzing were used to determine sucralose. Given that the spectroscopic method of analysis requires specific preparation of samples is insufficiently accurate and sensitive, and the chromatographic method is expensive, the electro-analytical method of determination was chosen for the research. This is justified by the structure of the molecule (it contains functional groups that can be oxidized electrochemically). Electrochemical experiments were carried out using a potentiostat-galvanostat on a three-electrode setup with a glassy carbon electrode as a working electrode, a platinum electrode as an auxiliary electrode and a silver chloride electrode for comparison. The study utilized non-carbonated beverages Continente (Portugal) and Xixo (Hungary), as well as carbonated beverages Sumol Zero (Portugal) and Fanta Shokata (Ukraine).The manufacturer indicated the presence of sucralose in all of them. Based on the conducted research and corresponding calculations, it was established that the beverages are safe for consumption. Natural processes of photo-, photoelectro-, and electrodegradation in soil and wastewater reduce the problems of sucralose accumulation in the environment. Therefore, to prevent diffusion to the anode space with the release of gaseous chlorine, membrane electrolysis is applied (the membrane is made of polyvinylpyridine), which separates the cathode and anode spaces and does not allow chloride ions to reach the anode. In this case, water electrolysis or electrooxidation of hydroxyl ions occurs at the anode with the formation of gaseous oxygen. Electroanalytical determination of sucralose was also conducted using the method of cyclic voltammetry. The fact that the electrochemical determination of sucralose took place can be judged by a gradual but sharp increase in the current value at certain potential values. In this case, the intensity of this increase depends on the concentration of the sweetener. A solution with a neutral pH level was used as the background electrolyte. Materials based on carbon (graphite, carbon nanotubes) were used as the working electrode. We proposed a new method for determining sucralose, associated with the dependence of the peak current value during its electrochemical oxidation on the concentration. At the same time, a linear relationship between the peak current value and the sweetener concentration is maintained.

Tryptophan (TRP) in the human body is generally metabolized by two different pathways, to serotonin or via kynurenine (KYN), where the majority is consumed through the latter. Studies relate that the imbalance between these two pathways is associated with different types of diseases. This work aims to investigate for the first time the redox properties of KYN in aqueous electrolytes on glassy carbon electrode (GCE), using electrochemical techniques, cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). The electrooxidation of KYN was compared with the anodic behavior of aniline and kynurenic acid. The KYN oxidation mechanism was proposed and occurs in the 2‐aminobenzoyl group from a main step with the withdrawal of one electron and the formation of an intermediate cation radical (KYN+•). The KYN+• follows a dimerization and polymerization reaction, forming different electroactive products (polyKYNs) that are adsorbed on the GCE surface. The EIS data indicated that the adsorbed polyKYNs films on GCEs in a strongly acidic medium (pH = 0.3) are conductive and in a physiological medium they are resistive, hindering new subsequent reactions. All redox reactions identified were dependent on an acid–base equilibrium, since they were strongly influenced by the pH of the medium, occurring more easily in alkaline media. The diffusion coefficient of KYN was determined in phosphate buffer pH = 7.0 as 1.59 × 10−6 cm2 s−1. The voltammetric responses of DP were also explored here for the development of a sensitive electroanalytical method for detection and quantification of KYN. For the development of the method, analytical parameters were studied, such as work concentration range, linearity, limit of detection (LOD) and quantification (LOQ), repeatability, reproducibility, and selectivity to possible interferences. A method using DPV and GCE was developed for determination of KYN in acidic medium (pH = 0.30) with a LOD of 0.43 μmol L−1.

Abstract Electroanalysis of melatonin, known as the sleep hormone, in the presence of its precursors, L‐tryptophan and 5‐hydroxy tryptophan in biological matrixes is an attractive research topic. The interference of voltammetric oxidation signals of these compounds, which have similar chemical structures, causes their determination to be challenging. This project aims to conduct a real‐time electroanalysis of melatonin and its precursors in biological samples using a novel nanocomposite platform. The new platform incorporates multi‐walled carbon nanotubes (MWCNTs), gold nanoparticles (GNPs), and graphitic carbon nitrides (g‐C 3 N 4 ) placed on a glassy carbon electrode surface. The voltammetric oxidation peak of melatonin can be effectively separated from other precursors on this new surface. Thus, melatonin can be easily determined electrochemically in the presence of its precursors. In optimized conditions, this electroanalytical method displayed a linear response range between 5.0 × 10 −7 to 1.0 × 10 −5 mol/L for both melatonin and 5‐hydroxy tryptophan and 5.0 × 10 −8 to 1.0 × 10 −6 mol/L for L‐tryptophan. Furthermore, the proposed modified electrode was successfully applied to determine melatonin and its precursors in various real samples such as human plasma, urine, and pharmaceutical formulations. The new sensor revealed excellent precision, remarkable simplicity, acceptable selectivity, good reproducibility, long‐term stability, and a rapid response toward melatonin, L‐tryptophan, and 5‐hydroxy tryptophan in biological matrixes.

Terbinafine hydrochloride (TBF) is a broad-spectrum antifungal used to treat various dermatophyte infections affecting the skin, hair, and nails. Accurate, sensitive, and affordable analytical methods are crucial for quantifying this drug. In this study, we report on the use of carbon-based electrodes for the electrochemical determination of TBF in pharmaceutical samples, including raw materials and tablets. Notably, for the first time in the literature, we employ screen-printed carbon electrodes (SPCE) for TBF quantification. Additionally, glassy carbon electrodes (GCE) were used to explore the redox behavior of the analyte. Electrochemical performance was evaluated and compared using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Optimized conditions of supporting electrolyte and scan rate studies revealed that the oxidation of TBF involves an equal exchange of protons and electrons. For the GCE, the oxidation process was found to be irreversible, controlled by both diffusion and adsorption, while for the SPCE, it was irreversible and diffusion-controlled. Square wave voltammetry (SWV) was optimized for both electrodes to enhance sensitivity. For SPCE, the calibration curve ranged from 5 to 100 μg mL-1, with an LOD of 1.48 μg mL-1 using a single drop of sample. The calibration curve for GCE was constructed between 2.5 and 30 μg mL-1, with a limit of detection (LOD) of 0.072 μg mL-1. TBF quantification was performed on raw material samples from various suppliers and tablet forms using external calibration with a recovery range within 90-110%. Analysis of the data reveals that the voltammetric method's accuracy aligns well with the chromatographic approach based on high performance liquid chromatography (HPLC). Furthermore, the proposed methodology demonstrated outstanding sustainability, achieving a score of 0.91 in Green Analytical Chemistry (GAC) criteria. Our novel approach combines high analytical efficiency with a reduced environmental impact, establishing itself as a green, cost-effective, and accurate alternative for TBF sensing.