https://www.abechem.com/ Analytical and Bioanalytical Electrochemistry en daily 1 Sun, 31 Aug 2025 00:00:00 +0330 Sun, 31 Aug 2025 00:00:00 +0330 https://www.abechem.com/article_733508.html In redox systems that obey the Nernst equation, where the surface and bulk concentrations remain in equilibrium during the potential sweep, the Randles-Sevcik equation is seen as a standard tool in both fundamental and applied linear scan voltammetry. As the Randles-Sevcik equation is seen as a key theoretical framework for interpreting voltammetric behavior in electrochemically reversible and diffusion-controlled redox systems considered under conditions of linear scan voltammetry, this foundational relationship becomes inapplicable when extended to pulse voltammetric techniques. Pulse voltammetric techniques differ fundamentally from linear scan voltammetric methods in both potential modulation and in current measurement protocols. The form of applied bias in pulse voltammetric techniques leads to conditions in which each applied pulse disrupts the diffusion profile of redox species of interest. Repeated disruption and compression of diffusion profiles in pulse voltammetric techniques introduce significant complexity into the current-potential behavior of redox species, thereby precluding the direct application of the Randles-Sevcik formalism. This study presents some basic theoretical insights into the limitations of applying Randles–Sevcik-type equations to square-wave voltammetry. In addition, a unifying parameter has been identified that governs the peak current response in square-wave voltammetry, which integrates the effects of potential step, frequency, square-wave amplitude, and temperature. At constant magnitude of the diffusion coefficient, this critical parameter is defined as χ = constant · (F/RT)·[Esw/(dE·f)]1/2 and it is seen as a foundation for developing more comprehensive models and analytical expressions describing peak current dependencies under square-wave voltammetric conditions. https://www.abechem.com/article_733509.html In this study, a novel voltammetric sensor for the detection of bisphenol A (BPA) was developed using a reduced graphene oxide (rGO) electrode incorporated with a TiO2-NiO-MnO2 nanocomposite (rGO/TNM). The TNM nanocomposite was synthesized via a hydrothermal method, and its integration with rGO improved the sensor’s electrochemical performance by enhancing conductivity, surface area, and active sites. Characterization of the TNM nanocomposite using X-ray diffraction (XRD) confirmed the formation of distinct anatase TiO2, γ-MnO2, and NiO phases, each contributing to the synergistic enhancement of electrocatalytic properties. Fourier-transform infrared (FTIR) spectroscopy indicated the presence of characteristic metal-oxygen bonds, validating the successful formation of the TNM nanocomposite. Scanning electron microscopy (SEM) revealed a highly uniform and porous morphology with well-dispersed nanoparticles, ideal for maximizing electron transfer. Elemental analysis through energy-dispersive X-ray (EDX) spectroscopy further confirmed the purity and composition of the nanocomposite. Under optimal conditions, the linear range of the rGO/TNM electrode by CV measurement was from 0.1 μg.L-1 to 1.0 μg.L-1, with a sensitivity and limit of detection (LOD) at 0.01094 µg.L-1. These results make the developed sensor a promising candidate for environmental monitoring of BPA and highlight the potential of nanocomposite-modified electrodes in advancing electrochemical sensor technology. https://www.abechem.com/article_733510.html The electrochemical conversion of carbon dioxide (CO₂) represents a promising strategy for reducing greenhouse gas emissions and facilitating sustainable chemical production. Here, we present a rationally engineered copper foam electrode integrated with a multifunctional nanohybrid comprising copper oxide (Cu₂O), bismuth sulfide (Bi₂S₃), and sulfur-doped graphene (SGr–Bi₂S₃). The Cu/Cu₂O–SGr–Bi₂S₃ composite leverages synergistic electronic and catalytic interfaces, resulting in outstanding electrocatalytic performance for CO₂ reduction. Comprehensive physicochemical and electrochemical analyses, including cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy, demonstrate that the hybrid electrodes deliver significantly higher cathodic current densities and exhibit markedly reduced charge transfer resistance under CO₂-saturated conditions compared to unmodified copper counterparts. The nanoscale distribution of Bi₂S₃ effectively increases the density of active catalytic sites, while strong electronic coupling at the heterointerfaces suppresses the competing hydrogen evolution reaction. As a result, the Cu/Cu₂O–SGr–Bi₂S₃ nanohybrids achieve superior activity, enhanced current densities, and excellent operational stability, outperforming conventional copper-based electrodes. These results position the Cu/Cu₂O–SGr–Bi₂S₃ nanohybrids as highly efficient, scalable, and economically viable electrocatalysts for next-generation CO₂ reduction technologies. https://www.abechem.com/article_733513.html This study presents an integrated experimental and theoretical investigation into the corrosion inhibition of carbon steel in 1.0 M HCl using Piper nigrum seed extract and its poly(lactic-co-glycolic acid) or PLGA-based nanoformulation. Electrochemical analyses revealed that the nanoencapsulated system markedly suppressed anodic dissolution and cathodic hydrogen evolution, achieving inhibition efficiencies above 90% across a wide concentration range. Surface characterization via SEM, TEM, EDS, and FTIR confirmed the formation of a compact, adherent protective layer, with distinct shifts in C=O, C–O, and aromatic vibrational bands evidencing chemisorption of phytochemicals and polymer-assisted encapsulation. Complementary density functional theory (DFT) calculations and molecular dynamics (MD) simulations demonstrated strong electron donation, favorable adsorption geometry, and stable inhibitor–metal interactions with adsorption energies exceeding −170 kJ/mol. The combined findings establish a robust mechanistic basis for the inhibitor’s performance, highlighting the synergistic benefits of phytochemical constituents and nanocarrier encapsulation. The results not only underscore the promise of Piper nigrum as an eco-friendly corrosion inhibitor but also demonstrate how nanoengineering strategies can advance green chemistry approaches to industrial corrosion mitigation. https://www.abechem.com/article_733516.html Nickel-based complexes are increasingly studied due to their promising roles in medicine, catalysis, and energy storage. This review offers an in-depth survey of recent progress in the synthesis of nickel complexes, with emphasis on methods involving both organic and inorganic ligands. The influence of ligand type on the stability, geometry, and electronic characteristics of these complexes is discussed in detail. Key analytical techniques, such as UV-Vis spectroscopy, FTIR, NMR, and X-ray diffraction, are highlighted for their importance in characterizing the structure and composition of nickel complexes. The review also examines the electrochemical properties of these compounds, focusing on their redox behavior and potential applications as catalysts in energy-related processes. Critical factors influencing the performance and reactivity of nickel complexes, including ligand environment, nickel oxidation state, and coordination geometry, are identified and analyzed. This article aims to provide valuable insights for researchers focusing on the design, characterization, and diverse applications of nickel-containing complexes in various scientific fields. https://www.abechem.com/article_733519.html Celiac disease (CD), a chronic autoimmune disorder triggered by gluten ingestion in genetically predisposed individuals, continues to pose diagnostic and management challenges worldwide due to its diverse clinical presentations and often subtle symptomatology. Although public awareness of CD has increased alongside the expanding gluten-free food market, significant knowledge gaps persist regarding the disease's underlying immunopathology, comorbidities, and lifelong dietary implications. As accurate and timely diagnosis remains critical to prevent long-term complications, conventional serological assays and biopsies, while effective, are limited by invasiveness, resource dependency, and processing delays. In response, electrochemical biosensing platforms—leveraging nanotechnology, aptamer design, and microfluidic integration—have emerged as promising alternatives, enabling rapid, sensitive, and cost-effective detection of key gluten-related biomarkers such as anti-tTG and deamidated gliadin peptide antibodies. These innovations harness the advantages of nanostructured materials, label-free detection, and real-time signal acquisition to offer portable, minimally invasive solutions for clinical and food safety applications. Despite the complexity of transitioning from laboratory prototypes to commercially viable diagnostic tools, interdisciplinary advancements in sensor engineering, material science, and data analytics continue to refine the specificity, stability, and usability of these platforms. This review synthesizes current findings on public perception of CD, highlights diagnostic challenges, and explores the transformative potential of electrochemical and nanomaterial-enabled biosensors in achieving early detection, personalized monitoring, and improved quality of life for individuals affected by gluten-related disorders.