Understanding Baseline Drift in Laser-Induced Graphene Electrodes and Its Impact on Heavy Metal Detection by Anodic Stripping Voltammetry: Comparison with Glassy Carbon Electrode.

Highly sensitive electrochemical analysis of diuron utilizing Super P carbon black-bridged halloysite nanotubes/whisker carbon nanotubes conductive networks.

Bimetallic CuCo-based metal-organic framework/graphene oxide composite-modified electrode as an efficient miRNA-208a detection biosensing platform.

Laser-induced preparation of CuO/nanoporous carbon nanocomposites from Cu(II)-coordinated β-cyclodextrin precursors for sensitive electrochemical detection of nitrite in food.

Advanced electrochemical sensor based on nickel sulfide-tungsten carbide nanocomposite for trace detection of chlorpromazine in animal-based foods.

A nanostructured electrochemical sensing platform was engineered for fast and sensitive quantification of salivary biomarkers, enabling noninvasive approaches to disease diagnosis. The device was constructed by modifying a glassy carbon electrode with a graphene–gold nanoparticle (GNP) composite, which enhanced surface conductivity and accelerated electron transfer. Electrochemical and morphological characterization using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) verified successful electrode functionalization and uniform nanocomposite coverage. The fabricated sensor exhibited high sensitivity and selectivity toward glucose and cortisol in saliva, achieving detection limits in the micromolar range. In addition, the system demonstrated excellent reproducibility and operational stability when evaluated with human saliva samples. Overall, this nanostructured electrochemical interface represents a promising, low-cost, and portable platform for rapid salivary diagnostics, well-suited to point-of-care health monitoring applications.

Hydrogen peroxide (H2O2) plays a significant role in biological and environmental systems. Therefore, it is crucial to develop an efficient biosensor for H2O2 determination, which is important in environmental monitoring and biomedical diagnostics. In this work, we have synthesized an amine functionalized, single-layered Ti3C2Tx MXene (NH2-S-Ti3C2Tx), which was modified over a glassy carbon electrode (GCE) to construct NH2-S-Ti3C2Tx/GCE. Thus obtained NH2-S-Ti3C2Tx/GCE was utilized as a platform for the covalent cross-linking of water-soluble horseradish peroxidase (HRP) enzyme through a glutaraldehyde coupling reaction to form HRP/NH2-S-Ti3C2Tx/GCE. The fabricated HRP/NH2-S-Ti3C2Tx/GCE biosensor demonstrated a well-defined redox peak with a formal potential of -0.45 V, corresponding to the FeIII/FeII redox center of HRP. Additionally, the designed biosensor has been employed towards the electrocatalytic detection of H2O2 under both static and dynamic conditions. The HRP/NH2-S-Ti3C2Tx/GCE sensor displayed a broad linear range of 20 µM to 1160 µM with a low limit of detection of 5.3 µM and a high sensitivity of 0.078 µA mM-1 cm-2. The reported sensor demonstrated excellent analytical performance due to direct electron transfer through the covalent immobilization of HRP over NH2-S-Ti3C2Tx. Furthermore, the sensor was employed for the real-time detection of H2O2, and it portrayed good recovery results.

• A leakless IL/poly(IL) gel electrolyte was evaluated for BPA detection • The IL/poly(IL) gel prevents BPA oxidation fouling and electrode passivation • Mild electrode polarisation yields 100% current retention over five SWV scans • This protocol works on Pt thin-film, Pt macrodisk and glassy carbon electrodes A novel anti-fouling strategy has been developed to fully prevent electrode passivation caused by the polymeric by-products from bisphenol A (BPA) electrochemical oxidation. In this work, we utilise a gelled electrolyte comprised of a mixture of an ionic liquid (IL, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C 2 mim][TFSI]) and a poly(ionic liquid) (poly(IL), poly(diallyldimethylammonium) bis(trifluoromethylsulfonyl)imide, poly[DADMA][TFSI]) to detect BPA. We demonstrate that the IL-based gelled electrolyte possesses an inherent anti-fouling effect, which can be further enhanced by applying mild electrode polarisation prior to BPA detection. Square wave voltammetry (SWV) measurements for BPA oxidation with electrode polarisation confirms the elimination of electrode fouling, demonstrating up to 100% of residual current values across five consecutive measurement cycles (RCV 1-5 ). The polarisation step was shown to be effective on both platinum and glassy carbon electrodes. As a proof-of-concept, electrochemical sensing experiments demonstrated a linear response to BPA concentrations from 200 to 1,200 µM, with a sensitivity of 2.4 nA/µM and a limit of detection of 44 µM.

Electro-oxidation of nitrite with TiO2 nanoparticles functionalized with Co(II) 5(4-carboxyphenyl)-10, 15, 20-tris(phenyl)porphyrin modified glassy carbon electrode

Bi–Cu–Co₃O₆ nanosheet incorporated MWCNT modified glassy carbon electrode for electrochemical detection of 4-Nitrotoluene in environmental water samples

Ultrasensitive cathodic electrochemiluminescence immunoassay for C-reactive protein enabled by boron-doped diamond electrodes and quantum dot nanospheres.

Prostate-specific antigen (PSA), which is a significant biomarker of prostate cancer, is quantified for the development of the diagnosis and treatment of prostate cancer. In this study, a new electrochemical immunosensor was fabricated using a hybrid material (CP@MWCNT) composed of multiwalled carbon nanotubes (MWCNT) and carbazole pyranine (CP) polymer. Pyranine was functionalized with 4-(9H-carbazol-9-yl)aniline for polymerization, and amine groups were used to increase antibody immobilization. The resulting pyranine polymer was synthesized via oxidative polymerization in MWCNT media in the presence of an FeCl3 catalyst. The characterization, thermal stabilities, and surface morphologies of the CP@MWCNT and CP were elucidated using FT-IR, UV-vis spectroscopy, TGA, SEM, and TEM. CP@MWCNT mixed with chitosan was drop-cast onto glassy carbon electrodes. Favorable analytical performance was confirmed by differential pulse voltammetry (DPV), with a broad linear range (0.0001-1 ng/mL) and low LOD (limit of detection) and LOQ (limit of quantification) values of 0.12 pg/mL and 0.36 pg/mL, respectively. The demonstrated immunosensor showed good selectivity against various antigens, along with high reproducibility (RSD of 0.93%) and excellent long-term stability. Moreover, the immunosensor proved suitable for commercial blood serum analysis, with analytical accuracy and reliability validated through recovery studies and comparison with a commercially available ELISA (enzyme-linked immunosorbent assay) kit.

Dopamine (DA) is a key neurotransmitter regulating nervous system function, while epinephrine (EP) is an important hormone reflecting pathological status. The accurate detection of these two molecules is of great clinical significance for the early diagnosis and therapeutic evaluation of related diseases. Metal-organic frameworks (MOFs) exhibit considerable potential in electrochemical sensing; however, pristine MOFs suffer from poor conductivity. In this work, the ligand H6L, a derivative of cyclotriveratrylene containing six carboxylic groups, was synthesized. A Co-L MOF was then constructed via a solvothermal method, and its crystal structure was determined and discussed. Then, Co-L was compounded with mesoporous carbon (MC) to give the composites for the modification of an electrode. Benefiting from the MC, the conductivity of the composite was significantly enhanced, and the electrochemical sensors containing the composite for the detection of DA and EP were constructed. Cyclic voltammetry (CV) was used to optimize of testing conditions, and differential pulse voltammetry (DPV) was used to detect the contents of analytes. For the detection of DA, the Co-L@MC(1:2)/GCE (ES-I) sensor displayed a linear range of 0.05-35 μM and a detection limit of 1.09 nM (GCE = glassy carbon electrode). For EP, the Co-L@MC(2:1)/GCE (ES-II) sensor possessed the linear range of 0.03-75 μM, and the detection limit was 1.55 nM. Meanwhile, both sensors exhibited good selectivity, repeatability, and stability, with all relative standard deviations (RSDs) below 5%.

Thermal stress is a major environmental factor affecting honeybee (Apis mellifera) physiology, colony stability, and overall welfare. Here, we report a novel electrochemical fingerprinting strategy based on differential pulse voltammetry (DPV) combined with supervised chemometric modeling for the discrimination of thermally stressed honeybee larvae. Larvae were exposed to optimal brood temperature (34.5°C) or mild hyperthermic conditions (36.0°C for 1h), and their electrochemical responses were recorded using glassy carbon electrodes modified with a carboxylated multiwalled carbon nanotube/Kolliphor dispersion. The resulting voltammetric profiles exhibited two reproducible anodic signals, including a peak associated with octopamine (OA), a key neurochemical mediator of stress. Partial least squares discriminant analysis (PLS-DA) models were constructed using the complete voltammetric profile and selected signal regions. The model based on the full DPV fingerprint achieved the best predictive performance, reaching an accuracy of 0.96 in the independent test set, whereas models based on individual peak regions showed lower discrimination capability. These results demonstrate that the complete electrochemical fingerprint provides a more comprehensive representation of the physiological response to thermal stress than single-analyte analysis alone. The proposed strategy introduces a shift from targeted electrochemical quantification toward multivariate physiological fingerprinting, offering a rapid and robust tool for environmental stress monitoring and honeybee welfare assessment. To the best of our knowledge, this is the first study to combine DPV-based electrochemical fingerprinting with supervised chemometric classification for the assessment of thermal stress in honeybee larvae.

The accurate determination of lenalidomide (LEN) is essential due to its widespread clinical use and narrow therapeutic window. In this context, a novel, eco-friendly electrochemical sensor based on a ZnFe-LDH@MnO₂ nanocomposite-modified glassy carbon electrode (ZnFe-LDH@MnO₂/GCE) was developed for the sensitive determination of LEN. The hybrid nanocomposite was synthesized via a rapid two-step procedure involving microwave-assisted formation of ZnFe-LDH followed by controlled MnO₂ deposition. Structural and physicochemical characterization using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, Field emission scanning electron microscopy/Energy dispersive X-ray spectroscopy (FE-SEM/EDX), Brunauer-Emmet-Teller (BET) analysis, and Thermogravimetric analysis (TGA) confirmed the successful formation of a hierarchically structured nanocomposite with a significantly increased surface area (113.88 m2/g for ZnFe-LDH@MnO₂ vs. 77.40 m2/g for ZnFe-LDH) and improved thermal stability. Electrochemical studies revealed enhanced electron-transfer kinetics, evidenced by a decrease in charge-transfer resistance (Rct) from 3218.7 Ω to 1050.1 Ω and an increase in electroactive surface area from 0.085 cm2 to 0.14 cm2 after modification. LEN exhibited an irreversible oxidation process involving a 2e⁻/1H⁺ mechanism, which was quantitatively monitored using differential pulse voltammetry (DPV). Under optimized conditions, the sensor demonstrated a wide linear range of 0.50-9.80µM (R2 = 0.995), with a low limit of detection (LOD) of 6.99nM. The developed platform showed excellent repeatability (relative standard deviation, RSD = 1.1%) and reproducibility (RSD = 0.4%), along with high selectivity against common interfering species. Furthermore, the environmental impact of the method was evaluated using Green Analytical Procedure Index (GAPI), Analytical GREEnness (AGREE) (0.84), and Blue Applicability Grade Index (BAGI) (77.5) tools, confirming its sustainability and practical applicability. The sensor was successfully applied to human plasma, synthetic urine, and pharmaceutical dosage forms, yielding satisfactory recoveries (98.2%-101.7%). These results demonstrate that the proposed sensor provides a green, sensitive, and cost-effective alternative for routine LEN determination in clinical and pharmaceutical analysis.

An electrochemical sensor for ultrasensitive and wide-range detection of the food additive potassium ferrocyanide based on signal attenuation mechanism of a poly(caffeic acid) film.

Rhodanese-enabled signal conversion and nanoporous gold electrotransduction for dual sensing of cyanide and sulfite in environmental waters.

The direct electrochemical detection of geosmin, a pervasive odor-causing compound in water, poses a longstanding analytical challenge owing to its exceptionally high oxidation potential. Here, we introduce a groundbreaking sensing architecture that achieves unprecedented direct anodic oxidation of geosmin using ultrathin, defective Zn2Ti3O8 spinel nanosheets synthesized via a simple graphene oxide (GO)-confined growth. This innovative confined approach unexpectedly stabilizes a defective Zn2Ti3O8 phase in a two-dimensional (2D) morphology, enabling superior charge transport and robust electrode-solution interfacial interactions. Integrated onto a glassy carbon electrode (GCE), the resulting platform dramatically lowers the overpotential for geosmin oxidation, circumventing the intrinsic limitations of conventional electrochemical sensors. Under optimized voltammetric conditions, the sensor delivers a linear dynamic range of 0.36-3.6 μg mL-1, with limits of detection (LOD) and quantification (LOQ) of 0.08 and 0.27 μg mL-1, respectively. The device exhibits excellent reproducibility, satisfactory recovery in spiked samples, and robust tolerance to common interferents. Beyond superior analytical metrics, this novel material establishes a simplified electrochemical approach for direct electrochemical monitoring of odorants in aqueous matrices, opening promising avenues for the design of affordable, portable sensors for real-time water quality assessment in field settings.

Antibiotic residues in environmental, food, and biological systems have become a serious global public health concern. Signal overlap occurs among structurally similar antibiotics, posing a significant challenge to the accurate identification and quantification of multicomponent antibiotics in complex systems. Here, we propose an intelligent electrochemical strategy that integrates a single-electrode four-channel platform with machine learning for the simultaneous detection of six antibiotics (amoxicillin, chloramphenicol, ciprofloxacin, enrofloxacin, norfloxacin, and ofloxacin). By modulating the scan direction and solution pH, multidimensional fingerprint signals were obtained via square wave voltammetry (SWV) at a glassy carbon electrode modified with poly(p-aminobenzenesulfonic acid), HKUST-1, and Au-Pt nanoparticles. Machine learning algorithms were then applied to decode these complex signals and extract discriminative features. The multilayer perceptron (MLP) achieved a classification accuracy of 99.75% for the six antibiotics in PBS, while the convolutional neural network (CNN) showed excellent regression performance with R2 > 0.9990 for concentration prediction. The trained CNN model was further validated in complex real samples, including milk, environmental water, and serum, maintaining R2 > 0.9850. Even in serum, the prediction accuracy for six antibiotics remained above 0.9964, with detection limits reaching the picomolar level. In addition, the electrocatalytic mechanisms of the antibiotics were investigated through electrochemical analysis, combined with conceptual density functional theory (CDFT) calculations. Overall, this work establishes a new paradigm for intelligent electrochemical sensing through the integration of electrode engineering, signal acquisition, and artificial intelligence, providing a promising strategy for rapid and accurate detection of multiple trace pollutants in complex matrices.

Performing direct CO2 reduction reaction (CO2RR) from flue gas streams containing low-concentrated CO2 (4-25% v/v) represents an opportunity to obtain added value products while reducing anthropogenic emissions. The heterogenization of molecular complexes offers a pathway to scale up CO2RR systems, especially under CO2 diluted conditions where the reactant is mass transport limited and the competitive hydrogen evolution reaction (HER) might be boosted. In this work, a formate-selective rhodium complex ([Rh(bpy')(Cp*)Cl]Cl, where bpy' = 4-(2-propyn-1-yloxymethyl)-4'-methyl-2,2'-bipyridine and Cp* = pentamethylcyclopentadienyl) is immobilized at high loading within tridimensional (3D) vertically aligned mesoporous silica films (VAMSF) electrochemically grown on glassy carbon electrodes. The resulting modified 3D electrodes allow direct CO2RR under both pure and diluted (10% v/v) CO2 streams, remaining selective for formate production in both organic and aqueous media and minimizing the contribution of HER from the support. In acetonitrile/1% H2O, Faradaic efficiencies (FE) for formate production of 66% in 100% CO2 and 47% in 10% CO2 were achieved, while in KHCO3 (pH= 6.8), FE of 47% and 43% were reached under pure and diluted CO2 streams, respectively. Finally, in a more acidic aqueous solution (pH= 3.8), FE of 59% was achieved under pure CO2. The electrodes work without preactivation or auxiliary overlayers and show recyclability and stability over multiple electrolysis cycles, indicating no structural degradation under operation conditions. To our knowledge, this is the first formate-selective heterogenized molecular complex tested under a diluted CO2 gas stream. These results reveal VAMSF as an attractive platform for bringing molecular CO2RR catalysis closer to realistic applications.