Electroanalysis最新文献

A unitized reversible fuel cell (URFC) is a promising technology that combines the functions of hydrogen production and electricity generation in a single device. However, the insufficient corrosion resistance of the bifunctional oxygen electrode significantly limits the large-scale implementation of this technology. This work investigates the influence of different architectures of the catalytic layer (CL) (layered and mixed loading of electrocatalysts, as well as the application of a titanium carbonitride (TiCN) sublayer) on the efficiency and durability of the oxygen electrode in fuel cell (FC) and water electrolyzer (WE) modes. A protocol for assessing electrode durability is proposed, involving cyclic recording of i–V curves in FC/WE modes, followed by testing the electrode in a potentiostatic mode at 1.65 V and 80°C for 30 min. The use of an electrode with a TiCN sublayer deposited by magnetron sputtering between platinum and iridium electrocatalysts doubled the device's service life compared to using a mixed loading of electrocatalysts. This effect is attributed to the reduced rate of Ir conversion to its oxidized form (IrO_x) due to the competitive oxidation of titanium in the sublayer, which also inhibits further corrosion processes.

This study investigates the electrochemical behavior of uric acid (UA) in the presence of ascorbic acid (AA) using differential normal pulse voltammetry (DNPV), aiming to establish a rapid and reliable method for UA detection without electrode modification. In DNPV, interference from AA was effectively suppressed by its pre-oxidation during the initial potential pulse. A systematic evaluation of pulse parameters revealed that a first-pulse width of 1000 ms and a pulse amplitude (ΔE) of 0.15 V provided optimal conditions, under which AA was almost completely depleted and the current response was dominated by UA oxidation. Under these optimized conditions, UA could be selectively quantified over the range of 0–300 μM, even in the presence of 100 μM AA. Application to human urine samples demonstrated good agreement with results obtained from enzymatic colorimetric assays, validated through the standard addition method after 100-fold dilution.

Food safety is crucial for human health, which is compromised by contaminants such as chemicals and pathogens. These contaminations are one of the major causes of mortality and morbidity in humans. Electrochemical biosensors are an impactful tool for the detection of these contaminants by altering the electrochemical signal due to the interaction between an analyte and a biorecognition element. The recognition element is the main component of an electrochemical biosensor where the analyte interacts. Biorecognition elements for contaminant detection include bacteriophages, DNA, peptides, aptamers, antibodies, polymers, enzymes, whole cells, and combinations of two or more recognition elements. This review focuses on the applicability of all biorecognition elements for the detection of various bacteria, viruses, mycotoxins, pesticide residues, heavy metals, and illegal additives that are most commonly present in food. The data on progress for the detection of all contaminants, including target analytes, working electrodes, recognition elements, electrochemical methods, limit of detection (LOD), standard deviation, and electrode stability.

Food safety is crucial for human health, which is compromised by contaminants such as chemicals and pathogens. These contaminations are one of the major causes of mortality and morbidity in humans. Electrochemical biosensors are an impactful tool for the detection of these contaminants by altering the electrochemical signal due to the interaction between an analyte and a biorecognition element. The recognition element is the main component of an electrochemical biosensor where the analyte interacts. Biorecognition elements for contaminant detection include bacteriophages, DNA, peptides, aptamers, antibodies, polymers, enzymes, whole cells, and combinations of two or more recognition elements. This review focuses on the applicability of all biorecognition elements for the detection of various bacteria, viruses, mycotoxins, pesticide residues, heavy metals, and illegal additives that are most commonly present in food. The data on progress for the detection of all contaminants, including target analytes, working electrodes, recognition elements, electrochemical methods, limit of detection (LOD), standard deviation, and electrode stability.

Precise detection of biomolecules is crucial for disease diagnosis. Traditional detection methods suffer from limitations such as slow results and high costs, restricting their practical application. While electrochemical sensors offer advantages such as rapid detection, ease of operation, and low cost, they are fundamentally constrained by electrode materials. Among numerous candidates, MXene stands out due to its unique 2D structure, enormous specific surface area, excellent conductivity, and abundant surface functional groups (e.g., the electron transfer rate constant of Ti₃C₂Tx exceeds that of conventional materials by 2–3 orders of magnitude), making it one of the ideal materials for electrochemical sensor fabrication. This article comprehensively reviews the latest advances in MXene-based electrochemical sensors for biomolecular detection. It systematically elucidates sensing principles, performance metrics, and material design strategies and for the first time distils a “design grammar” for MXene-based sensors. This establishes universal design principles linking material characteristics (e.g., terminal functional groups and heterostructures) to detection performance (e.g., achieving a glucose detection limit at the aM level). Analysis indicates these rules can guide the construction of sensing interfaces that simultaneously achieve ultrahigh sensitivity, selectivity, and stability. This design framework not only points the way for developing high-performance MXene sensors but also provides a critical theoretical framework and practical guide for rational optimization and novel sensing interface design in electroanalytical chemistry, advancing its practical applications in clinical diagnostics and personalized medicine.

Precise detection of biomolecules is crucial for disease diagnosis. Traditional detection methods suffer from limitations such as slow results and high costs, restricting their practical application. While electrochemical sensors offer advantages such as rapid detection, ease of operation, and low cost, they are fundamentally constrained by electrode materials. Among numerous candidates, MXene stands out due to its unique 2D structure, enormous specific surface area, excellent conductivity, and abundant surface functional groups (e.g., the electron transfer rate constant of Ti₃C₂Tx exceeds that of conventional materials by 2–3 orders of magnitude), making it one of the ideal materials for electrochemical sensor fabrication. This article comprehensively reviews the latest advances in MXene-based electrochemical sensors for biomolecular detection. It systematically elucidates sensing principles, performance metrics, and material design strategies and for the first time distils a “design grammar” for MXene-based sensors. This establishes universal design principles linking material characteristics (e.g., terminal functional groups and heterostructures) to detection performance (e.g., achieving a glucose detection limit at the aM level). Analysis indicates these rules can guide the construction of sensing interfaces that simultaneously achieve ultrahigh sensitivity, selectivity, and stability. This design framework not only points the way for developing high-performance MXene sensors but also provides a critical theoretical framework and practical guide for rational optimization and novel sensing interface design in electroanalytical chemistry, advancing its practical applications in clinical diagnostics and personalized medicine.

In this work, a disposable screen-printed carbon electrode (SPCE) modified with multiwalled carbon nanotubes (MWCNTs) and molecularly imprinted polymer (MIP) was developed for the determination of Paraquat (PQ) in water and food samples, using adsorptive square wave voltammetry. The MIP was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), and the results confirmed its composition and chemical bonds. Under optimized conditions, the sensor exhibited two linear response ranges (6.3–200 and 200–500 μmol L⁻¹), with R² = 0.99 and sensitivities of 0.13 and 0.10 µA/µmol L⁻¹, respectively. The limits of detection and quantification were 3.46 and 6.30 μmol L⁻¹. The method validation demonstrated precision, accuracy, stability, and sensitivity for PQ. Recoveries in water samples showed recovery values between 95.1% and 98.58%, while for food samples (acerola and apple), recoveries were between 83.9% and 97.3%. These results suggest the potential application of the sensor for PQ analysis in food and environmental control.

In this work, a disposable screen-printed carbon electrode (SPCE) modified with multiwalled carbon nanotubes (MWCNTs) and molecularly imprinted polymer (MIP) was developed for the determination of Paraquat (PQ) in water and food samples, using adsorptive square wave voltammetry. The MIP was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), and the results confirmed its composition and chemical bonds. Under optimized conditions, the sensor exhibited two linear response ranges (6.3–200 and 200–500 μmol L⁻¹), with R² = 0.99 and sensitivities of 0.13 and 0.10 µA/µmol L⁻¹, respectively. The limits of detection and quantification were 3.46 and 6.30 μmol L⁻¹. The method validation demonstrated precision, accuracy, stability, and sensitivity for PQ. Recoveries in water samples showed recovery values between 95.1% and 98.58%, while for food samples (acerola and apple), recoveries were between 83.9% and 97.3%. These results suggest the potential application of the sensor for PQ analysis in food and environmental control.

Synergies between the emerging field of organic bioelectronics and microbiology are paving the way for significant advances in biomedical research and medical technology. While in vitro models of infections form the foundation of our current understanding, they cannot replicate the complexity of biological systems. Organic bioelectronics, utilizing conjugated conducting polymers, bridge the gap between abiotic and biotic environments using ions and electrons as charge carriers. Polymer formulations can be easily tuned so that desirable electrochemical properties can be achieved and deposited for use as surface coatings, hydrogels, or 3D composites to monitor or control in vitro as well as in vivo systems. In this review, we explore the role of organic bioelectronics in infection management, highlighting their potential for modeling, detection, prevention, and treatment. These technologies offer new strategies to control microbial colonization, improve infection diagnostics, and enhance therapeutic approaches while addressing challenges such as antibiotic resistance.

Synergies between the emerging field of organic bioelectronics and microbiology are paving the way for significant advances in biomedical research and medical technology. While in vitro models of infections form the foundation of our current understanding, they cannot replicate the complexity of biological systems. Organic bioelectronics, utilizing conjugated conducting polymers, bridge the gap between abiotic and biotic environments using ions and electrons as charge carriers. Polymer formulations can be easily tuned so that desirable electrochemical properties can be achieved and deposited for use as surface coatings, hydrogels, or 3D composites to monitor or control in vitro as well as in vivo systems. In this review, we explore the role of organic bioelectronics in infection management, highlighting their potential for modeling, detection, prevention, and treatment. These technologies offer new strategies to control microbial colonization, improve infection diagnostics, and enhance therapeutic approaches while addressing challenges such as antibiotic resistance.