Electroanalysis最新文献

Cover picture provided by Dr. Elena Benito-Peña and Dr. Susana Campuzano. Electroanalysis covers all branches of electroanalytical chemistry, including both fundamental and application papers as well as reviews dealing with analytical voltammetry, potentiometry, new electrochemical sensors and detection schemes, nanoscale electrochemistry, advanced electromaterials, nanobioelectronics, point-of-care diagnostics, wearable sensors, and practical applications.

The Composite Centered Experimental Design (CCED) using the response surface methodology was used to optimize the synthesis of a hematite-geopolymer composite, applied to the preparation of a Pb²⁺ electrochemical sensor. Two important experimental parameters in the formulation (curing time and hematite content) were considered in the optimization of the synthesis of the composite material. The electrochemical signal of Pb²⁺ at a carbon paste electrode modified by the synthesized composite was used as a response to identify the best formulation. After applying the generated experimental plan, the optimal composite material was obtained using 17.08% hematite and a curing time of 0.16 days. The characterization of the optimized composite material revealed the presence of a porous structure and a poly(phospho-ferro-siloxo) network, but with a fraction of well dispersed and unreacted hematite. Preliminary experiments confirmed that the sensor prepared with the composite showed high stability and reproducibility of the Pb (II) signal, justifying its application for accurate sensing of the metal cation in an aqueous solution. A Pb²⁺ calibration curve was obtained after optimizing the experimental detection parameters (composition of the carbon paste electrode, pH of the accumulation solution, accumulation time, and electrolysis potential). A detection limit of 0.2 nM (based on a signal-to-noise ratio of 3) was obtained for a studied concentration range between 0.04 and 0.48 nM. The designed sensor also showed remarkable selectivity and excellent performance in real media samples (spring, tap, rain, and well water).

This study presents the development of a low-cost, easy-to-prepare carbon-based ink for printed electrodes using polyethylene terephthalate (PET) as the support material. The ink was composed of graphite and cellulose acetate (80 : 20%) mixed with acetone and cyclohexanone as solvents. The screen-printing technique, a versatile and economical method that allows the printing of high-thickness films, was used to produce the sensor. The developed sensor was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM), demonstrating good electrochemical behavior with a well-defined peak corresponding to the redox probe and a low background current. The optimization process focused on analyzing and discussing the ink manufacturing process and characterizing the materials used. The performance of the fabricated printed electrode was evaluated using a potassium ferrocyanide probe as a model redox system. The proposed sensor has the potential for use in electroanalytical determinations and can be produced at a low cost of US$ 0.897 per unit. This study aims to contribute to the development of printed sensors that can be produced on a large scale, are disposable, and can be used to determine different analytes.

In this study, novel materials combining palladium-imprinted polymers (PdIP) with single-walled carbon nanotubes (SWCNTs) were developed to modify screen-printed electrodes (SPEs) and tested as sensors for detecting palladium ions. The arrangement of the SWCNTs-PdIP network is crucial for the electrochemical performance of the material. Therefore, we compared two types of materials: one with covalent linkages and the other with non-covalent linkages between the SWCNTs and the polymer. The materials were characterized using Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, scanning electron microscopy, and porosimetry. Cyclic and differential pulse voltammetry demonstrated a significant improvement in the electrochemical properties of the material with covalent linkages between PdIP and SWCNTs. The results confirmed the performance of the proposed SWCNTs-X/PdIP-based electrochemical sensor for detecting palladium ions. They showed a linear relationship in the concentration range of 0.06–1.5 mmol L⁻¹, and the estimated limit of detection (LOD) was 0.026159 mmol L⁻¹ (S/N=3). The constructed sensor showed high analytical sensitivity (675.46 μA mmol⁻¹ L cm⁻²), good repeatability (RSD=4.05 %), and recovery (97 %).

The rapid development of organ-on-chip (OOC) technology has been propelled by advancements in micro-nanofabrication processes and cell culture technologies. Researchers envision OOCs as models capable of simulating the functionality and structure of specific organs, aiming to develop microenvironmental models that encapsulate key physiological parameters. The gut has long been one of the most important organs in the human body, crucial for ensuring the digestion and absorption of nutrients and maintaining interconnected functions with other organs. Consequently, the development of gut-on-chip (GOC) has garnered significant attention. Integrating sensors into GOCs capable of monitoring relevant physical and chemical parameters within the chip is imperative for evaluating the functionality of the internal environment. This review summarizes and outlines integrated sensor technologies for GOCs, introduces manufacturing processes for OOCs, reviews relevant technologies for integrating microsensors with OOCs, and examines works combining sensors and GOCs to monitor simulated physiological parameters such as trans-epithelial resistance, oxygen levels, and other parameters. Additionally, attention is given to relevant technologies from other OOCs that could be applicable for monitoring in GOCs, providing insights for GOC detection technologies.