Basal Plane Pyrolytic Graphite Electrode Research Articles

A study on redox reactions of the azo dye Sudan I and its hydroxylated metabolites on pyrolytic graphite and boron doped diamond electrodes to support electrochemical studies of metabolic transformations

Sudan I (1-(Phenyldiazenyl)naphthalen-2-ol) is an orange industrial azo dye. It is utilized as a marker substrate in studies of metabolic transformation of xenobiotics through processes involving cytochrome P450 hydroxylase. In this complex study, redox and subsequent chemical/electrochemical reactions of Sudan I and its three major metabolites (4′‑hydroxy, 6‑hydroxy, and 4′,6-dihydroxy derivatives of Sudan I) were investigated using boron doped diamond and basal plane pyrolytic graphite electrodes. Cyclic voltammetry (CV) in Britton – Robinson buffer pH 7 showed distinct differences in the number and potential of signals, depending on the number and positions of the hydroxy groups. While in CV scans initiated in anodic direction, primary oxidations of paired or unpaired hydroxy groups are dominating, cathodic scans lead primarily to reduction of the azo group and to cleavage of the parent compounds and formation of 1-aminonaphthalen-2-ol and aniline or their corresponding hydroxylated derivatives. These are oxidizable in reverse anodic scans. Combinations of CV scans can be used to distinguish among all tested compounds. Basal plane pyrolytic graphite electrode provides better sensitivity than boron doped diamond electrode due to enhanced adsorption of the aromatic analytes/intermediates. The possibility of detecting Sudan I and its metabolites in the presence of excess amounts of NADPH as an essential component of enzymatic hydroxylation systems, was tested. Although the oxidation signal of NADPH partially interferes with signals of primary oxidation of hydroxy groups (particularly for Sudan I), our results suggest that electrochemical assays could be applicable in monitoring transformation of Sudan I in biochemical studies.

The use of hybrid electrochemical double-stranded DNA/2′-deoxyguanosine 5′-monophosphate (bio)sensors based on anodically pre-treated “basal-plane” pyrolytic graphite electrode for monitoring of the interaction between double-stranded DNA and neonicotinoid insecticide clothianidin

We present the utilization of the novel hybrid electrochemical DNA biosensor, as well as the fabrication and testing of novel dGMP (2′-deoxyguanosine 5′-monophosphate) (bio)sensor based on anodically pre-treated “basal-plane” pyrolytic graphite electrode (BPPGE) for the investigation of the interaction between double-stranded DNA (dsDNA) and neonicotinoid insecticide clothianidin (CLOT) via linear-sweep voltammetry (LSV). The results clarify the nature of the interaction as partial-intercalation (marked by high preference towards guanine bases) with binding constant (Kb) of 8.1 × 105 L/mol, free Gibbs energy (∆G0) of −33.154 kJ/mol, and site-binding size (s) of 0.58 bp. The conclusions obtained by LSV are further supported by molecular docking that confirmed a partial-intercalative mode of interaction with the predominant involvement of the hydrogen bonds (exclusively with the guanine bases) for the stabilization of dsDNA-CLOT complex.

Electrochemical Sensor for Meropenem Therapeutic Monitoring in Human Plasma Based on Carbon Nanotubes Modified Basal Pyrolytic Graphite Electrode

Sensitive, precise, and fast differential pulse voltammetric (DPV) method has been developed for determination of meropenem (MER) in pure form, pharmaceutical dosage form, and human plasma. The fabricated sensors are based on basal-plane pyrolytic graphite electrode (BPPGE) substrates that was modified by coating the surface with carbon nanotubes. The modified electrode showed detectable enhancement of the anodic peak current of meropenem from 25.8 to 35.7 μA. Effect of both pH and scan rate on peak current and potential were studied, optimum conditions were found to be at pH = 3.0 and scan rate of 100 mV.s−1. A linear response was obtained over the concentration range of 3.0 × 10−7 to 7.0 × 10−5 M MER in aqueous buffer solution. The suggested sensor is highly sensitive, has short response time, capable of MER detection as low concentration as 1.5 × 10−6 M in human plasma. The proposed sensors shows a great potential towards future fabrication of a point-of-care device to monitor MER level in patients’ plasma to ensure drug safety and efficacy for patients in intensive care unit.

Comparative study of boron-doped diamond, basal-plane pyrolytic graphite, and graphite flake paste electrodes for the voltammetric determination of rivaroxaban and dabigatran etexilate in pharmaceuticals and urine samples

As anticoagulants, rivaroxaban (RIV) and dabigatran etexilate (DAB) are high-risk drugs that can cause life-threatening bleeding. They are a group of drugs that require optimal dosing, therefore their monitoring in the patient is of great importance, especially in emergencies. In this study, we developed a rapid, sensitive square-wave voltammetric (SWV) method by using boron-doped diamond, graphite flake paste, and basal-plane pyrolytic graphite electrodes (BDDE, GFPE, and BPPGE, respectively) to determine the presence of anticoagulants, namely, RIV and DAB in pharmaceutical and urine samples. The supporting electrolyte composition and SWV parameters were investigated. The sensitivity, stability, recovery, calibration curve, and limit of detection (LOD) of the developed method were evaluated. Under the optimal experimental condition, a wider linear response was achieved using BDDE in the detection of both RIV and DAB. The calibration curve for RIV was in the range of 0.5–30.0 μmol L−1 for BDDE and 1.0–10.0 μmol L−1 for GFPE. The calibration curve for DAB was in the range of 0.01–0.7 μmol L−1 for BDDE and 0.07–1.0 μmol L−1 for BPPGE, which shows a linear relationship between the concentration of DAB and the anodic current. LOD was equal to 0.145 μmol L−1 (for RIV at BDDE), 0.297 μmol L−1 (for RIV at GFPE), 2.78 nmol L−1 (for DAB at BDDE), and 16.7 nmol L−1 (for DAB at BPPGE). Finally, BDDE, GFPE, and BPPGE were applied to detect the presence of RIV and DAB in pharmaceuticals and spiked urine samples with satisfactory results (98.2–100.5% for RIV and 99.22–102.8% for DAB). Cyclic voltammetry (CV) was applied to understand the electrode mechanism of RIV and DAB oxidation. The character of RIV and DAB signals was irreversible and diffusion-controlled. In addition, the roughness factor (RF) of BDDE, GFPE, and BPPGE was investigated, which were equal to 0.367, 0.558, and 0.422, respectively.

A Comparison of Edge‐plane and Basal‐plane Pyrolytic Graphite Electrodes towards Sensitive Determination of the Fungicide Mandipropamid

AbstractA sensitive square‐wave voltammetry (SWV) method based on basal‐plane pyrolytic graphite electrode (BPPGE) and edge‐plane pyrolytic graphite electrode (EPPGE) was developed to determine the concentration of the pesticide mandipropamid (MAN) in spiked river water and grape juice samples. Under optimal experimental conditions, the SWV response of EPPGE and BPPGE was linear over the concentration ranges of 0.7 to 9.0 μmol L−1 and 0.5 to 10.0 μmol L−1, respectively. The method was successfully used to determine MAN in spiked samples with good recovery. Cyclic voltammetry (CV) was conducted to understand the mechanism underlying the electrode process of MAN.

Voltammetric study of triazole antifungal agent terconazole on sp3 and sp2 carbon-based electrode materials

Terconazole belongs to synthetic triazole antifungal agents, inhibiting biosynthesis of ergosterol or other sterols and thus disrupting cell wall synthesis in fungi. In this study, electrochemical behavior of terconazole was studied for the first time using cyclic voltammetry and differential pulse voltammetry on boron doped diamond electrode (BDD) with different surface treatments leading to O-terminated, H-terminated and polished surfaces, as well as on glassy carbon (GCE) and basal-plane pyrolytic graphite electrodes (PGE). Terconazole is not reducible within the potential window on these electrode materials. It is oxidizable in aqueous solutions in pH range from 2.0 to 12.0 in two steps due to the presence of piperazine ring in its molecule, possessing two redox centers at the tertiary nitrogen atoms, by an ECE mechanism. Optimal conditions were found for determination of terconazole in 0.1 mol L−1 phosphate buffer pH 7.2. Using differential pulse voltammetry, the lowest detection limit of 0.40 μmol L−1 and excellent repeatability (RSD 1.1%) were achieved on O-terminated BDD when in-situ anodic activation was used prior to each scan. This is beneficial in comparison with GCE and PGE; their necessity of ex-situ polishing worsens the signal repeatability (RSD ~ 4%) and detection limits reaching 0.50 μmol L−1 and 1.23 μmol L−1, respectively.

Copper oxide impregnated glassy carbon spheres based electrochemical interface for nitrite/nitrate sensing

Copper oxide impregnated glassy carbon spheres (CuxOGCS where x = 1or2) modified basal plane pyrolytic graphite electrode (CuxOGCS-BPPGE) was demonstrated as electrochemical interface for nitrite/nitrate sensing. The CuxOGCS were synthesized by impregnating glassy carbon spheres GCS with 0.5 M CuNO2 solution followed by thermal treatment at 823 K. Electrochemical and spectroscopic studies of the composites confirms the copper oxide formation during synthesis. The electrocatalytic oxidation/reduction studies of the nitrite/nitrate on a CuxOGCS-BPPG electrode has been studied by cyclic voltammetry (CV). The detection limits obtained were 1.032 μg L−1 for nitrate and 2.038 μg L−1 for nitrite respectively. The sensitivity of the method was about 1500 μA μM−1 cm−2 for nitrite determination. It has been demonstrated that the composite electrode can be used to analyze nitrate/nitrite in soil and fruit juice samples.

Constant-current chronopotentiometric stripping detection of bovine serum albumin on silver amalgam particles

Highly sensitive peak H registered by constant-current chronopotentiometric stripping (CPS) analysis relates due to the catalytic hydrogen evolution reaction of proteins adsorbed on mercury-based surfaces including recently introduced silver amalgam particles (AgAPs). Since the peak H allows a structure-sensitive analysis of proteins, including those important in biomedicine and cancer research, it has been systematically studied by CPS analysis using AgAPs in this work. Conditions of AgAPs' electrodeposition on basal plane pyrolytic graphite electrode (bPGE) were optimized towards CPS analysis of model protein (bovine serum albumin, BSA) using peak H. Optimized condition for bPGE-AgAP preparation allowed sensitive CPS detection of either native or denatured BSA down to 10 nM concentration, a discrimination between both forms, and registration of the BSA thermal denaturation kinetic. Obtained results have confirmed the applicability of AgAPs in protein electroanalysis and may contribute to the further development of novel (bio)sensors or (bio)electrochemical applications using micro-volume batch, flow-through or lab-on-chip detection systems.

Electrodeposited silver amalgam particles on pyrolytic graphite in (spectro)electrochemical detection of 4-nitrophenol, DNA and green fluorescent protein

Catalytic properties and high adsorption affinity of nucleic acids and proteins to silver amalgam electrode surface make this kind of electrified interface perspective for bioanalytical and biomedical applications. For the first time, a basal-plane pyrolytic graphite electrode (bPGE) has been used as a substrate for electrodeposition of silver amalgam particles (AgAPs). Optimization of the resulting composition, surface morphology and electrochemical properties of the AgAPs was done by scanning electron microscopy with energy disperse X-ray spectroscopy, image processing software and voltammetric detection of electrochemically reducible model organic nitro compound, 4-nitrophenol. Spectro-electrochemical applicability of bPGE-AgAP has been demonstrated by electrolysis of 4-nitrophenol. Simultaneous UV–Vis-chronoamperometry provided information on the number of exchange electrons and the reduction rate constants. Preferential adsorption of the fluorescently labelled calf thymus DNA and the green fluorescent protein (GFP) on the surface of AgAPs was observed by fluorescence microscopy. In contrast to previously studied indium-tin oxide and vapour-deposited gold decorated by AgAPs, herein the presented bPGE-AgAP has provided sufficiently wide negative potential window allowing direct electroanalysis of non-labelled DNA and GFP using intrinsic electrochemical signals independently of the fluorescent labelling. The bPGE-AgAP can thus be expected to find application opportunities in protein electrochemistry, (bio)sensor development or in-situ spectro-electrochemical studies.

Voltammetric monitoring of a solid-liquid phase transition in N,N,N\u2032,N\u2032-tetraoctyl-2,6-diamino-9,10-anthraquinone (TODAQ)

Exploratory experiments on effects from a phase transition are reported for a low-melting microcrystalline anthraquinone (N,N,N′,N′-tetraoctyl-2,6-diamino-9,10-anthraquinone or TODAQ). Data for the solid-liquid phase transition are obtained by differential scanning calorimetry and then compared to data obtained by voltammetry. In preliminary electrochemical measurements, microcrystal deposits on a basal plane pyrolytic graphite electrode are shown to undergo a solid-state 2-electron 2-proton reduction in contact to aqueous 0.1 M HClO4 with a midpoint potential Emid,solid = − 0.24 V vs. SCE. The reduction mechanism is proposed to be limited mainly by the triple phase boundary line and some transport of TODAQ molecules towards the electrode surface for both solid and melt. A change in the apparent activation energy for this reduction is observed at 69 °C, leading to an enhanced increase in reduction current with midpoint potential Emid,liquid = − 0.36 V vs. SCE. A change of TODAQ transport along the crystal surface for solid microcrystalline material (for the solid) to diffusion within molten microdroplets (for the liquid) is proposed. Upon cooling, a transition at 60 °C back to a higher apparent activation energy is seen consistent with re-solidification of the molten phase at the electrode surface. Differential scanning calorimetry data for solid TODAQ dry and for TODAQ in contact to aqueous 0.1 M HClO4 confirm these transitions.Graphical

Step potential as a diagnostic tool in square-wave voltammetry of quasi-reversible electrochemical processes

By applying square-wave voltammetry (SWV) and through examining the most common electrochemical kinetic region, i.e. the quasi-reversible charge transfer process, the important role of the step potential (height, ΔE) was theoretically and practically studied considering both, the dissolved as well as the electrode surface confined redox species. It was found that the impact of the step potential is readily manifested through the scan rate (v) of an SWV experiment, the one being the product of the frequency of pulses (f) and the step potential (v = ΔE f). The presented studies evidently confirmed that the role of the step potential is very complex but that it significantly affects the morphology of both, the forward as well as the backward SWV current components, which applies for any degree of electrochemical reversibility. Furthermore, it was demonstrated that in case of quasi-reversible electrochemical reactions the degree of reversibility profoundly depends on the step potential applied. Moreover, it was proven that the degree of reversibility can be markedly improved by correspondingly decreasing ΔE. This has significant importance in the context of electrode kinetics as well as in analytical applications. Hence, this study clearly demonstrated that besides the frequency, the step potential can be an additional important tool for inspecting and improving the electrode kinetics in SWV. Finally, in order to test a practical example of a quasireversible electrode reaction of a dissolved redox couple, the SWV measurements of theFe3+(aq)/Fe2+(aq) redox couple were carried out using a basal plane pyrolytic graphite electrode and the resulting readings confirmed our theoretical predictions.

Vicinal Diol-Tethered Nucleobases as Targets for DNA Redox Labeling with Osmate Complexes.

Six-valent osmium (osmate) complexes with nitrogenous ligands have previously been used for the modification and redox labeling of biomolecules involving vicinal diol moieties (typically, saccharides or RNA). In this work, aliphatic (3,4-dihydroxybutyl and 3,4-dihydroxybut-1-ynyl) or cyclic (6-oxo-6-(cis-3,4-dihydroxypyrrolidin-1-yl)hex-2-yn-1-yl, PDI) vicinal diols are attached to nucleobases to functionalize DNA for subsequent redox labeling with osmium(VI) complexes. The diol-linked 2'-deoxyribonucleoside triphosphates were used for the polymerase synthesis of diol-linked DNA, which, upon treatment with K2 OsO3 and bidentate nitrogen ligands, gave the desired Os-labeled DNA, which were characterized by means of the gel-shift assay and ESI-MS. Through ex situ square-wave voltammetry at a basal plane pyrolytic graphite electrode, the efficiency of modification/labeling of individual diols was evaluated. The results show that the cyclic cis-diol (PDI) was a better target for osmylation than that of the flexible aliphatic ones (alkyl- or alkynyl-linked). The osmate adduct-specific voltammetric signal obtained for OsVI -treated DNA decorated with PDI showed good proportionality to the number of PDI per DNA molecule. The OsVI reagents (unlike OsO4 ) do not attack nucleobases; thus offering specificity of modification on the introduced glycol targets.

Oxidation potentials of guanine, guanosine and guanosine-5′-monophosphate: Theory and experiment

Guanine, having lower one-electron oxidation potential than other nucleobases, is of relevance to oxidative degradation of nucleic acids in mutagenesis, carcinogenesis, and aging. Here we compare oxidation potentials of guanine (G), guanosine (Guo), deoxyguanosine (dGuo), guanosine -5′- monophosphate (GMP) and 2′- deoxyguanosine -5′- monophosphate (dGMP) obtained by theoretical and experimental methods. Structures of G species were optimized and the identities of minima were verified by vibration frequency calculations. Redox equilibria were modelled in terms of corresponding thermochemical cycles. The changes in free energy were calculated at DFT level using the two different functionals: (i) general purpose B3LYP functional, and (ii) more specific ωB97X-D functional (both with 6-31 + G(d) basis set). Experimental oxidation potentials of all G analogues were measured voltammetrically on a polymer pencil graphite electrode (pPeGE) providing the best results from all carbon electrodes used (glassy carbon electrode, basal and edge plane pyrolytic graphite electrodes). The oxidation process is strongly dependent on the pH value and with increasing pH a linear shift of G oxidation peaks (Epa) towards negative potentials is observed. The theoretically and experimentally obtained oxidation potentials were compared for the pH 5. Anodic peak potentials increase in the order G « dGMP ≤ GMP < dGuo ≤ Guo and correlate with the calculated thermodynamic redox potentials as well as with NBO charges in purine moiety. The oxidation of deoxy analogues was predicted theoretically to occur at lower potentials than that of corresponding parent compounds and this fact was experimentally verified. The assumption that due to negatively charged phosphate group of GMP or dGMP their oxidation potentials could be observed at lower positive potential has not been confirmed and the significant difference (more than 200 mV) between the oxidation potentials of G nucleobase and its nucleosides and nucleotides is discussed. Moreover, conformity of theoretical and experimental data for radicals (cation, neutral) indicates that while the deprotonation process of G differs from its analogues, the oxidation process of all species takes place on imidazole ring.

Influence of Carbon Material Properties on Activity and Stability of the Negative Electrode in Vanadium Redox Flow Batteries: A Model Electrode Study

The V2+/V3+ reaction occurring at the negative electrode in the all-vanadium redox flow battery has been identified as performance limiting in the system. Given the complexity of the commercial carbon electrodes typically used for this application, a model electrode approach is adopted in this work to study electrode activity and stability. This was done using edge and basal plane pyrolytic graphite electrodes modified by electrochemical oxidation. Differential electrochemical mass spectrometry was used for the first time in this work to investigate the parasitic hydrogen evolution reaction on the oxidized carbon surfaces. The basal plane surface showed a higher faradaic efficiency for V3+ reduction compared to that for the edge plane surface. The oxidized surfaces were subject to extended cycling, after which the basal electrode showed a dramatic loss in activity compared to the edge surface which was relatively stable. This activity loss was related to the poor mechanical stability of the basal plane su...

Optimising carbon electrode materials for adsorptive stripping voltammetry

Different types of carbon electrode materials for adsorptive stripping voltammetry are studied through the use of cyclic voltammetry. Capsaicin is utilised as a model compound for adsorptive stripping voltammetry using unmodified and modified basal plane pyrolytic graphite (BPPG) electrodes modified with multi-walled carbon nanotubes, carbon black or graphene nanoplatelets, screen printed carbon electrodes (SPE), carbon nanotube modified screen printed electrodes, and carbon paste electrodes. We compare the analytical performance of the different electrodes in terms of sensitivity and limit of detection, concluding that carbon electrodes modified with high surface area material exhibit an improvement of sensitivity. In terms of limit of detection, increasing the electrode surface area however does not improve the detection limit; the limit of detection is similar for all electrodes studied.

Multiwalled Carbon Nanotube Modified Electrodes for the Adsorptive Stripping Voltammetric Determination and Quantification of Curcumin in Turmeric

AbstractA sensitive electrochemical method for the determination and quantification of curcumin using adsorptive stripping voltammetry (AdsSV) at a multiwalled carbon nanotube modified basal plane pyrolytic graphite electrode (MWCNT‐BPPG electrode) is presented exploiting the high surface area of the latter. Next the voltammetric behaviour of curcumin on the modified electrode is examined and AdsSV shown to be a sensitive method for quantifying curcumin. The adsorption of curcumin on the electrode surface is evidenced to follow a Langmuir adsorption isotherm. Linear calibration for curcumin in the range of 2–100 μM was obtained with a detection limit of 0.45 μM and a limit of quantification of 1.49 μM. For application to real samples of turmeric, a one‐step sample preparation in ethanol has developed providing a simple and rapid extraction procedure. The MWCNT‐BPPG electrode with AdsSV allowed the determination of curcumin equivalent in turmeric powder sample with recoveries in the range of 92–108 %. This facile and fast method will be useful for monitoring the quality of curcumin containing in commercial turmeric products.

The Mediatorless Electroanalytical Sensing of Sulfide Utilizing Unmodified Graphitic Electrode Materials

The mediatorless electroanalytical sensing of sulfide is explored at a range of commercially available graphitic based electrodes namely, edge and basal plane pyrolytic graphite (EPPGE and BPPGE, respectively), boron-doped diamond (BDDE), glassy carbon (GCE) and screen-printed electrodes (SPE). The electrochemical performance is evaluated in terms of current density/analytical signal and oxidation potential, where the GCE and SPE are found to possess the optimal electrochemical responses. The electroanalytical performance of the GCE is explored towards the electrochemical sensing of sulfide and it is found that it is hampered by sulfide passivation, thus requiring pretreatment in the form of electrode polishing between each measurement. We demonstrate that SPEs provide a simple analytically comparable alternative, which, due to their scales of economy, create disposable, one-shot sensors that do not require any pretreatment of the electrode surface. To the best of our knowledge, this is the first report using mediatorless SPEs (bare/unmodified) towards the sensing of sulfide. In addition, the electroanalytical efficacy of the SPEs is also explored towards the detection of sulfide within model aqueous solutions and real drinking water samples presenting good apparent recoveries, justifying the plausibility of this graphitic mediatorless screen-printed platform.

Glass-like carbon, pyrolytic graphite or nanostructured carbon for electrochemical sensing of bismuth ion?

Different carbon electrodes were explored for application in electroanalysis, namely for sensing of bismuth ion as model analyte. Carbon materials tested included glassy carbon, basal and edge plane pyrolytic graphite, as well as nanostructured carbonized polyaniline prepared in the presence of 3,5-dinitrosalicylic acid. Bismuth ion was chosen as model analyte as protocol for its detection and quantifications is still to be determined. Herein, anodic stripping voltammetry was used with study of effect of several parameters such as scan rate and deposition time. Electrode based on carbonized polyaniline showed the highest activity for bismuth ion sensing in terms of the highest current densities recorded both in a laboratory and in real sample, while basal plane pyrolytic graphite electrode gave the lowest limit of detection.

Anodized Edge-plane pyrolytic graphite for electroanalysis of pantoprazole in tablet dosage forms and human urine samples

Electroanalytical parameters of different graphitic carbon-based electrode materials were compared to select the best one for the pantoprazole electroanalysis. Such parameters include sensitivity, repeatability, residual background current, and signal-to background current ratio of the analytical response and such electrodes include conventional carbon-based electrodes such as glassy carbon (GC), carbon paste, edge-plane pyrolytic graphite (EPPG), and basal-plane pyrolytic graphite electrodes and film-coated modified GC electrodes with graphitic carbon-based materials such as carbon nanotube, nanographene, carbon black and graphite powder. The EPPG electrode, after applying a simple electrochemical anodization, showed more acceptable analytical performances compared with the other electrodes. Raman spectroscopy was employed to study the surface structural changes that occurred dring the anodic activation. Calibration plot with a good linearity was obtained in the concentration range of 0.2-25 and 0.02-8.5 µM, and the detection limit was estimated to be 0.055 and 0.0041µM using cyclic voltammetry and differential pulse voltammetry techniques, respectively. Finally, the electrochemically activated EPPG electrode was used successfully for the determination of pantoprazole in tablet dosage forms and human urine samples with satisfactory results.

Comparative Study of Basal-Plane Pyrolytic Graphite, Boron-Doped Diamond, and Amorphous Carbon Nitride Electrodes for the Voltammetric Determination of Furosemide in Pharmaceutical and Urine Samples

Sensitive and simple electroanalytical methods were developed for the determination of the loop diuretic furosemide (FUR) in pharmaceutical formulations and synthetic urine samples by coupling square-wave voltammetry (SWV) with polished basal-plane pyrolytic graphite (BPPG) or cathodically pretreated boron-doped diamond (BDD) and amorphous carbon nitride (a-CNx) as working electrodes. The analytical parameters obtained with the three methods were compared. With BPPG, best results were attained using 0.10molL−1 H2SO4 as supporting electrolyte, whereas with BDD and a-CNx, this was attained using a 0.040molL−1 BR buffer (pH 4.5). Cyclic voltammograms obtained for FUR evidenced an irreversible behavior (with two oxidation peaks), in agreement with the literature. On the BDD and a-CNx electrodes, the electrooxidation of FUR is a purely diffusion-controlled process, whereas on the BPPG electrode some degree of adsorption is also involved. The obtained linear response ranges (detection limits) for the BPPG, BDD, and a-CNx electrodes were 0.60–4.8 (0.47), 0.30–13 (0.30), and 0.50–99 (0.39) μmolL−1, respectively. The proposed methods were successfully applied in the determination of FUR in pharmaceutical formulations (tablets), with results similar to those obtained using a reference spectrophotometric method (at a confidence level of 95 %), and in the recovery of FUR in synthetic urine samples. The analytical conditions obtained with the novel SWV methods here reported are comparatively better than those for other electrochemical methods in the literature. As the pretreatment procedures are much simpler for BDD and a-CNx than for BPPG, one can conclude that the former two materials can be advantageously used to determine FUR with good sensitivity and selectivity.