Unmodified Boron-doped Diamond Electrode Research Articles

Development of an environmentally friendly method for the determination of prednisolone in natural waters using unmodified boron-doped diamond electrode

Development of an environmentally friendly method for the determination of prednisolone in natural waters using unmodified boron-doped diamond electrode

A simple and reliable electrochemical method employing an unmodified boron-doped diamond electrode for the determination of triclocarban

Since the advent of the COVID-19 pandemic, triclocarban-containing cleaning products have been increasingly consumed. As triclocarban is an emerging compound, it is necessary to develop new sensors for its monitoring. So, a simple and reliable electroanalytical method for the determination of triclocarban using an unmodified boron-doped diamond electrode was developed. The application of a cathodic pretreatment (−2.0 V, 30 min, 0.5 mol L−1 H2SO4) on the electrode surface provided higher current intensities and lower resistance to charge transfer in contrast to the non-treated surface. On the diamond electrode surface, the triclocarban showed an irreversible behavior with two oxidation peaks at +1.10 and +1.40 V vs. Ag/AgCl, KCl(sat). The hypothesis for removing hydrogens of both amide groups of the triclocarban structure was supported by computational methodology which also explained the broadened oxidation peaks and the distance between them. The calibration curve for triclocarban, obtained by using differential pulse voltammetry in a supporting electrolyte composed of McIlvaine buffer (pH 3.0) and ethanol (80:20 v/v), covered a concentration range of 1.0 to 50 μmol L−1, and it exhibited a detection limit of 0.31 μmol L−1 under optimized experimental conditions. Using an accumulation time of 120 s at open circuit potential, a calibration curve by differential pulse adsorptive stripping voltammetry was constructed in a range of 0.05 to 20 µmol L−1 of triclocarban, with a detection limit of 18 nmol L−1. Triclocarban quantification assays were carried out on samples of antibacterial soaps and river water, and data were recorded with acceptable precision and accuracy.

Quantification of ferulic acid using square-wave voltammetric method at an unmodified boron-doped diamond electrode

Quantification of ferulic acid using square-wave voltammetric method at an unmodified boron-doped diamond electrode

Utilizing epicatechin voltammetric oxidation signal for the estimation of total phenolic content in the tea samples via the unmodified boron-doped diamond electrode surface

In this work, the boron-doped diamond (BDD) electrode surface was employed for the first time in conjunction with the epicatechin (EC) oxidation signal to estimate the total phenolic content of tea samples by voltammetry. During cyclic voltammetry analysis of the EC, an easily identifiable, irreversible, and adsorption-controlled oxidation peak was observed at around +1.05 V (vs. Ag/AgCl) in HNO3 solution. Our experimental setup was fine-tuned by investigating the effect of electrode pretreatment, pH of the supporting electrolyte, accumulation factors, and instrumental parameters on the oxidation peak response of EC. When measuring EC in a 0.1 mol L−1 HNO3 solution at +1.0 V, square-wave adsorptive stripping voltammetry provided a highly linear response (at open-circuit accumulation for 30 s). The dynamic range was determined to be between 1.0 and 50.0 μg mL−1 (3.4510−6–1.7210−4 mol L−1), while the detection limit was found to be 0.28 μg mL−1 (9.6510−7 mol L−1). Selectivity studies were performed with other phenolic compounds found in tea such as epigallocatechin gallate, catechin, tannic acid, and gallic acid. Finally, by assessing the total phenolic content in the black and green tea samples, the suggested approach's applicability was shown by providing an estimate of the EC equivalents present in the samples.

A simple and fast flow injection amperometry for the determination of methimazole in pharmaceutical preparations using an unmodified boron-doped diamond electrode.

In this work, an automated flow injection analysis (FIA) connected to a boron-doped diamond electrode (BDDE) was originally developed for the analysis of methimazole in pharmaceutical preparations. At a modification-free BDDE, methimazole was easilly oxidized. For the analysis of the mechanisms occurring at the electrode surface, cyclic voltammetry was employed to evaluate the impact of fundamental experimental parameters, such as pH and scan rate, on the BDDE response. For the quantitative detection, the FIA amperometric approach was constructed and used as a fast and sensitive method. The suggested approach provided a broad linear range of 0.5-50 μmol/L and a low detection limit of 10 nmol/L (signal-to-noise ratio = 3). Furthermore, the BDDE was successfully utilized to quantify methimazole in genuine samples from a variety of medicines, and its performance remained steady after more than 50 tests. The findings of amperometric measurements exhibit excellent repeatability, with relative standard deviations of less than 3.9 and 4.7 % for intra-day and inter-day, respectively. The findings indicated that, compared with traditional approaches, the suggested method has the following advantages: quick analysis time, simplicity, highly sensitive output, and no need for complicated operational processes.

The first electrochemical evaluation and voltammetric detection of the insecticide emamectin benzoate using an unmodified boron-doped diamond electrode

This study introduces for the first time an electroanalytical investigation and novel voltammetric method for the determination of emamectin benzoate (EB) using a cathodically pretreated boron-doped diamond electrode (CTP-BDDE). The CPT-BDDE electrode exhibited a well-defined irreversible signal at ∼1.35 V (vs. Ag/AgCl) using cyclic voltammetry. Different scan rates (from 10 to 750 mV s−1) suggested that the oxidation of EB on the BDDE surface is a diffusion-controlled process. Using square wave voltammetry, the anodic peak current was linear with EB concentrations from 0.25 mg L-1 to 12.5 mg L-1, with LOD and LOQ found to be 0.079 and 0.263 mg L-1, respectively. The effect of other insecticides used to treat sea lice and inorganic ions found in seawater on the voltammetric detection of EB was negligible. The proposed method was successfully applied to the determination of EB at different concentrations in real sea water samples. To the best of our knowledge, the voltammetric behaviour of EB and the electrochemical method for EB determination is reported for the first time.

An unmodified boron-doped diamond electrode for electroanalytical investigation and sensitive voltammetric quantification of antiviral drug famciclovir in the pharmaceutical formulation and serum samples

The current study offers an electroanalytical investigation and a novel voltammetric approach for the quantitative analysis of famciclovir (FCV) utilizing an unmodified boron-doped diamond (BDD) electrode. An irreversible, well-defined, diffusion-controlled anodic peak was observed at approximately +1.27 V (vs. Ag/AgCl) in acetate buffer solution (ABS, 0.1 mol L−1, pH 4.7) when the agent was tested using cyclic voltammetry. The voltammetric signals of the oxidation peaks are pH dependent (ranging from 2.0 to 7.0). Using square-wave mode, a good linear response was obtained for FCV quantification in 0.1 mol L−1 ABS (pH 4.7) solution at +1.26 V (vs. Ag/AgCl). Wide dynamic range was found for 0.1 to 50.0 μg mL−1 (3.11 × 10−7-1.56 × 10−4 mol L−1), with a low detection limit of 0.029 μg mL−1 (9.02 × 10−8 mol L−1). Applicability of the proposed method for the determination of FCV was demonstrated in the pharmaceutical formulation and model serum samples.

Electrooxidation of tetracycline antibiotic demeclocycline at unmodified boron-doped diamond electrode and its enhancement determination in surfactant-containing media

In this paper, for the first time, the study of voltammetric determination of tetracycline antibiotic demeclocycline was conducted. The oxidation of compound was investigated using a commercially available boron-doped diamond electrode pretreated electrochemically (anodic and subsequent cathodic). Addition of anionic surfactant, sodium dodecylsulfate (SDS) and cationic surfactant, cetyltrimethylammonium bromide (CTAB) to the demeclocycline-containing electrolyte solution at pH 2.0 and 9.0, respectively, was found to improve the sensitivity of the stripping voltammetric measurements. Employing square-wave stripping mode (after 30 s accumulation at open-circuit condition) in Britton-Robinson buffer, the limits of detection were found to be 1.17 μg mL−1 (2.3 × 10−6 M) for 4 × 10−4 SDS-containing buffer solution at pH 2, and 0.24 μg mL−1 (4.8 × 10−7 M) for 1 × 10−4 CTAB-containing buffer solution at pH 9.0. The feasibility of the developed approach for the quantification of demeclocycline was tested in urine samples.

Simultaneous Monitoring of Febuxostat and Uric Acid in Human Serum Samples Using the Direct Square-Wave Voltammetric Method

Background: High uric acid serum level, hyperuricemia, is now associated with many diseases such as gout, chronic kidney disease, hypertension, coronary artery disease and diabetes. Febuxostat is a novel selective xanthine oxidase inhibitor approved for the treatment of hyperuricemia. Objective: The aim of this study was to develop a first analytical method for the simultaneous determination of febuxostat and uric acid. Methods: An unmodified boron-doped diamond electrode provided concurrent quantitation of drug at low levels and uric acid, which has clinical significance in the diagnosis and therapy of hyperuricemia, at relatively high concentrations. The direct square-wave voltammetric method was applied to the analysis of both analytes in human serum samples. Results: Under the optimized conditions, the linear response of peak current on febuxostat concentration was achieved in the range from 7.5 × 10-7 to 3 × 10-5 M, while uric acid showed two linear ranges of 5 × 10-6 - 5 × 10-5 M and 5 × 10-5 - 2 × 10-4 M. The method was successfully utilised for quantification of both analytes in human serum samples. Good recoveries were obtained without interference from common inorganic cations and anions as well as glucose, dopamine, ascorbic and folic acids at concentrations expected in physiological conditions. Conclusion: The great benefits of developed method are fast analysis (only 7.5 s for run), low cost and simplicity of performance.

Application of unmodified boron-doped diamond electrode for determination of dopamine and paracetamol

For the first time the application of unmodified boron doped diamond electrode for dopamine (DA) and paracetamol (PA) determination in biological samples and pharmaceutical preparations with the use of differential pulse voltammetry was demonstrated in the present work. The wide linear range of calibration graphs: from 1 × 10−7 to 2 × 10−4 mol L−1 for DA and PA, and very low detection limits were achieved, equaling 1.87 × 10−8 mol L−1 for DA and 1.35 × 10−8 mol L−1 for PA. The proposed sensor was successfully applied for determination of dopamine in urine samples, paracetamol in syrups for children, and for simultaneous determination of paracetamol and dopamine in blood and serum samples.

Analytical Approach for Detection of Ergosterol in Mushrooms Based on Modification Free Electrochemical Sensor in Organic Solvents

Ergosterol (Erg) is the major sterol component in the plasma membranes of fungi. The main goal of this work was to develop rapid, reliable, and cost-effective method toward Erg detection based on application of unmodified boron-doped diamond electrode. Several organic solvents were tested (acetonitrile, dimethyformamide, dimethylsulfoxide, dichloromethane), and it was found that best analytical characteristics were achieved using acetonitrile containing 0.1 M tetrabutylammonium hexa-fluorophosphate as supporting electrolyte. Oval shaped and well-defined oxidation peak was recorded at potential of around 1.17 V versus Ag/Ag+ non-aqueous reference electrode. Under optimized experimental conditions, linear working range from 2 to 200 μM was estimated, with limit of detection of 0.7 μM, using square wave voltammetry. Negligible effect of possible interfering compound was observed. Proposed methodology was successfully applied for estimation of Erg content in mushrooms extract with satisfactory results in comparison with spectrophotometric procedure. Obtained results clearly show that developed analytical methodology can be adequate replacement for the, up to date, used methods and open-novel approach for ergosterol detection.

Boron-doped diamond electrode — A prestigious unmodified carbon electrode for simple and fast determination of bentazone in river water samples

Bentazone (BZ) is selective contact-past herbicide with suspected reproductive toxicity potential for human due to possible contamination of ground and surface waters. This work presents simple, rapid, sensitive and accurate determination of bentazone at unmodified boron-doped diamond electrode, using differential pulse voltammetry in Britton-Robinson buffer (pH4, oxidation peak at 1.0V). Under optimized DPV conditions linear calibration curve was obtained for range of 2 to 100μM, with a detection limit of 0.5μM. The effect of possible interfering agents is negligible, confirming good selectivity of the method. The method was successfully applied to determination of bentazone in spiked river water samples. This electrochemical determination of bentazone represents a favorable alternative to other used time-consuming and expensive analytical techniques and procedures.

Voltammetric detection of antimony in natural water on cathodically pretreated microcrystalline boron doped diamond electrode: A possibility how to eliminate interference of arsenic without surface modification

Very simple and fast electroanalytical method for the detection Sb(III) on chemically unmodified boron-doped diamond electrode (BDDE) has been developed. Voltammetric behavior of antimony was investigated in various acidic supporting electrolytes and the most suitable medium for the determination of Sb(III) on bare BDDE has been 6molL−1 HClO4 solution. The analytical performance was studied with differential pulse anodic stripping voltammetry (DPASV) with optimized conditions (deposition potential −1V vs. Ag/ AgCl and deposition time 240s). An analysis of possible effects due to the presence of other metal ions (especially As(III)) in the solution was eliminated using NaH2PO4 as supporting electrolyte with addition EDTA as selective complexing agent for Sb(III). Speciation of antimony was also investigated. The detection limit of this analytical strategy achieved value of 1.08 × 10−7molL−1. The proposed method was validated and applied for natural water from former antimony mines as real samples.

Oxidation and reduction of omeprazole on boron-doped diamond electrode: Mechanistic, kinetic and sensing performance studies

Voltammetric behavior of omeprazole on chemically unmodified boron-doped diamond electrode was investigated. Omeprazole is possible to oxidize and reduce in various supporting electrolytes. Both processes are strongly dependent on pH value of the solution. Well defined oxidation and reduction signal of omeprazole was observed at high and low pH values of supporting electrolyte. Kinetics of charge transfer in the pH range from 3 to 10 in various supporting electrolytes was studied and characterized by the estimation of formal potentials (+1.07 to +0.89V for oxidation and −0.95 to −1.18V for omeprazole reduction), charge transfer coefficients (0.52–0.33 for oxidation and 0.19–0.17 for reduction) together with standard heterogeneous rate constants. The analytical performance was studied with linear sweep voltammetry, square-wave voltammetry and differential pulse voltammetry. The lowest detection limit of 9.1×10−8molL−1 for oxidation of omeprazole was achieved by SWV technique. The proposed simple, sensitive and cheap method was validated and applied for pharmaceutical formulations and human urine as real samples.

Sensitive and selective determination of riboflavin (vitamin B2) based on boron-doped diamond electrode

In this paper, we present electrochemical behavior and determination of riboflavin in pharmaceutical tablets by square wave voltammetry using unmodified boron-doped diamond electrode. In Britton–Robinson buffer solution at pH 2, by employing cyclic voltammetry it is demonstrated that riboflavin undergoes a diffusion-controlled quasi-reversible electron transfer reaction. The experimental parameters, such as pH of the supporting electrolyte, square wave voltammetry parameters, influence of most common interferences, were examined. Under optimized experimental conditions in Britton–Robinson buffer solution at pH 2, linear calibration curves were obtained in the wide range from 0.02 to 35 µM, with the capability of detection of 0.0037 µM. Repeatability of ten measurements was calculated at four concentrations from linear range and all values were <1.8 %. Proposed method was successfully applied for the determination of the total vitamin content in pharmaceutical preparations and urine samples. The developed approach could be beneficial for the quantification of vitamin in drugs using boron-doped diamond electrode as up-to-date electrochemical sensor and could represent inexpensive analytical alternative to separation methods.

Determination of pyridoxine (vitamin B6) in pharmaceuticals and urine samples using unmodified boron-doped diamond electrode

Pyridoxine (vitamin B6, VB6) was detected in pharmaceutical preparation and human urine samples by employing differential pulse voltammetry (DPV) at unmodified boron doped electrode. In Britton–Robinson buffer solution (BRBS) at pH6, VB6 provides well defined oxidation peak at around +1.05V vs. Ag/AgCl (3M KCl). The influence of most of the interferents present in real samples, supporting electrolyte and DPV parameters was investigated. A VB6 sensor with and linear range from 7 to 47 and a detection limit of 3.76 was obtain after optimization. Repeatability of the proposed procedure calculated after 7 measurements of 9 and 30μM of VB6 was 3.6 and 2.4%, respectively. Proposed methodology was successfully applied for the determination of VB6 in real samples, and from obtained results, it can be concluded that proposed analytical procedure can be an inexpensive alternative to the widely used separation methods. Prime Novelty statementThis work presents the quantification of vitamin B6, using differential pulse voltammetry, with boron-doped diamond electrode. BDD electrode is, up to date, one of the best electrode materials, with extremely low background current and negligible passivation. The aim of this study was to develop method for vitamin B6 determination in various matrices, as can be seen from the results, the obtained procedure shows good recovery values in tested samples and could be a satisfactory replacement to the separation methods and modified electrodes.

Sensitive Electrochemical Detection of Oxalate at a Positively Charged Boron‐Doped Diamond Surface

AbstractAllyltriethylammonium bromide (ATAB) was covalently attached to the surface of hydrogen‐terminated boron‐doped diamond (BDD) thin films using a photochemical method to fabricate positively charged electrode surfaces. The anodic current for oxalate oxidation both in cyclic voltammetry and in flow‐injection analysis with amperometry was found to be up to two times larger at ATAB‐modified BDD (ATAB‐BDD) than at an unmodified BDD electrode, which may be based on the electrostatic interaction between the oxalate anion and the electrode surface. In addition, the stability of the electrochemical detection of oxalate was improved at the ATAB‐BDD electrode compared to the unmodified electrode.