Bare Boron-doped Diamond Electrode Research Articles

Electrochemical Diagnosis of Urinary Tract Infection Using Boron-Doped Diamond Electrodes.

Efficient detection of sodium nitrite in human urine could be used to diagnose urinary tract infections rapidly. Here, we demonstrate a fast and novel method for the selective detection of sodium nitrite in different human urine samples using electrolysis with a bare boron-doped diamond electrode. The measurement is performed without adding any other species, such as enzymes, and uses a simple electrochemical approach with an oxidation step followed by reduction. In the present study, we pay attention to the reduction potential range for the measurement, which is substantially different from many previous literature reports that focus on the oxidation reaction. The determination of added sodium nitrite based on cyclic voltammetry or differential pulse voltammetry is employed for two pooled urine samples and three individual urine matrices. From this, the linear response ranges for sodium nitrite detection are 0.5-10 mg/L (7.2-140 μmol/L) and 10-400 mg/L (140-5800 μmol/L). The results from these urine samples convert well to the calibration curve, with a limit of detection established as 0.82 mg/L (R2 = 0.9914), which is clinically relevant.

Platinum and palladium nanoparticles on boron-doped diamond for the electrochemical detection of hydrogen peroxide: a comparison study.

Hydrogen peroxide (H2O2) plays a role in many facets - a household item, an important industrial chemical, a biomarker in vivo, and several others. For this reason, its measurement and quantification in a variety of media are important. While spectroscopic detection is primarily used for H2O2, electrochemical methods offer advantages in versatility, cost, and sensitivity. In this work, we investigate a 2-step surface metal nanoparticle (NP) modification for platinum (Pt) and palladium (Pd) on boron-doped diamond (BDD) electrodes for the detection of H2O2. Several parameters such as the metal salt concentration and electrodeposition charge in the 2-step modification were varied to find an optimum. Using cyclic voltammetry (CV), the BDD-PdNP electrode types were found to yield a sharper, more well-resolved H2O2 oxidation peak compared to the BDD-PtNP electrodes. Both metal NP electrode types significantly improved the response compared to the bare BDD electrode; a 150-200× improvement in sensitivity was observed across all modified electrode types. Calibration experiments were completed at both low and high concentration ranges in stagnant and flow-based solutions. The lowest limit of detection (LOD) obtained was 50 nM (5E-08 M) on a BDD-PdNP electrode modified with 1.0 mM PdCl2 to 5.0 mC in the wet chemical seeding and electrodeposition steps. 0.25 mM PdCl2 to 3.23 mC and 0.25 mM HPtCl6- to 3.23 mC also yielded a sufficient response for low-level H2O2, with LODs around 100 nM (1E-07 M). Overall, this work exemplifies the wide applicability of BDD and achieves sub-μM H2O2 LODs with a non-enzymatic electrode material.

Determination of naproxen by using differential pulse voltammetry with poly (aniline-2-sulfonic acid) modified boron doped diamond electrode

In this study, an electrochemical sensor based on a boron doped diamond electrode (BDDE) was developed for the determination of naproxen (NAP) using a poly(aniline-2-sulfonic acid)/boron doped diamond electrode, p(A2SA/BDDE). Polymerization of A2SA was conducted in a water/acetonitrile (1:1) mixture containing 0.1 M sodium perchlorate (NaClO4) on bare BDDE and the electrochemical properties studied by cyclic voltammetry in ferricyanide/KNO3 solution. The prepared p(A2SA/BDDE) was used for detection of NAP. Effects of parameters such as monomer type and concentration, the number of cycles, and scan rate were investigated using differential pulse voltammetry (DPV) in phosphate buffer containing 0.75 mM NAP. The effect of electrolyte type and pH on DPV responses to NAP were also studied. The oxidative current peak stem from NAP concentration observed at 1.1 V potential. A linear calibration curve was obtained in the range of 0.05–1.00 mM NAP concentration. Correlation coefficient (R2), detection limit, and quantification limit were calculated as 0.9944, 0.0328 mM, and 0.1093 mM, respectively. In conclusion, it may be claimed that the modified electrode constructed in this work can be used successfully as a naproxen-selective membrane due to its ease of preparation, high R2 value, and good reproducibility.

Sensitive and cost-effective boron doped diamond and Fe2O3/Chitosan nanocomposite modified glassy carbon electrodes for the trace level quantification of anti-diabetic dapagliflozin drug

Dapagliflozin (DPG), used in the treatment of type 2 diabetes, is a drug widely used to treat type 1 diabetes with certain restrictions. Hypoglycemia, urinary tract, genital infections, and decreased body water are among the common side effects of DPG. The detailed electrochemical oxidation process of DPG at both electrodes was investigated using cyclic voltammetry. The bare boron-doped diamond electrode (BDDE) showed a diffusion-controlled process, while the glassy carbon electrode (GCE) was an adsorption-controlled process. Using iron (III) oxide/Chitosan nanocomposite showed (Fe2O3/Chitosan NCs) as the modification agent for the GCE, a highly sensitive and selective nanosensor was created for the DPG assay. Fe2O3/Chitosan NCs modified GC, and bare BDD electrodes were successfully applied for the electrochemical determination of DPG. The simple, eco-friendly, sensitive, and time-saving electroanalytical methods have been developed for the determination of DPG in urine, serum, and tablet samples using differential pulse (DPV) and adsorptive stripping differential pulse voltammetric (AdSDPV) methods with a BDDE and the proposed nanosensor (Fe2O3/Chitosan NCs modified GCE) in 0.1 M H2SO4 containing 20% methanol, respectively. Under optimized conditions, the developed methods gave detection limits of 2.0 nM and 15 nM and linear range of 0.1–8.0 μM and 0.6–80.0 μM for Fe2O3/Chitosan NCs modified GCE and BDDE, respectively. Both electrodes showed excellent recoveries (between 97.25 and 102.68 %) and repeatability with RSD lower than 2.4% (n = 5). The developed methods were successfully applied for the analysis of DPG in serum, urine, and pharmaceutical dosage forms.

A detailed EIS study of boron doped diamond electrodes decorated with gold nanoparticles for high sensitivity mercury detection

This work compares the electrochemical impedance response of polished and unpolished boron doped diamond (BDD) electrodes, during mercury detection measurements. For each substrate type both bare electrodes and electrodes decorated with average diameter 30 nm AuNPs were used, to investigate the role of AuNPs during mercury sensing with diamond electrodes. In square wave anodic stripping voltammetry (SWASV) measurements for mercury detection, the mercury ions in the electrolyte are deposited onto, then stripped from the diamond electrode surface. To investigate the different electrode performances during these steps, the EIS measurements were made at the deposition and stripping potentials, alongside scans at open circuit potential for comparison. The performance of the electrodes is assessed in terms of their electron transfer rate (k0). The electrodes decorated with AuNPs are shown to have lower capacitance and higher reactivity than the bare pBDD and BDD electrodes, until the mercury concentration in the electrolyte is < 500 µM, when the sp2/sp3 carbon ratio at the surface of the electrodes has a greater influence on the sensitivity for mercury detection than the presence of AuNPs.

Voltammetric detection of silver in commercial products on boron doped diamond electrode: stripping at lowered potential in the presence of thiosulfate ions

Bare boron-doped diamond electrode (BDDE) was applied for investigation of deposition/stripping processes of silver ions in various supporting electrolytes. The highest signal was observed in 0.1 mol dm−3 HNO3. Detection of silver ions is also possible in 0.1 mol dm−3 Na2S2O3 where Ag+ is strongly complexed as [Ag(S2O3)2]3−. Though the sensitivity is 100 times lower, the potential of anodic dissolution of silver is significantly shifted towards the negative values. This shift might be useful for solving of some interferences which may occur in the detection process. After preliminary cyclic voltammetry, the analytical performance was studied by differential pulse anodic stripping voltammetry (DPASV) and square-wave anodic stripping voltammetry. Deposition potential of − 0.18 V vs. Ag/AgCl and deposition time of 240 s were selected as optimum DPASV parameters. The lowest detection limit of 2.0 × 10–10 mol dm−3 was achieved with DPASV in HNO3. Negligible effect of possible interferents on Ag response proved to be a good selectivity of method. The proposed method after validation was also applied to real samples analysis of some commercial products with complex matrix. The obtained results are statistically identical with data declared by manufacturer and gained by independent technique, making this method suitable for commercial product control.

Electroanalysis of Gallic and Ellagic Acids at a Boron‐doped Diamond Electrode Coupled with High‐performance Liquid Chromatography

AbstractElectrochemistry of gallic acid (GA) and ellagic acid (EA) was investigated by cyclic voltammetry (CV) using a bare boron‐doped diamond (BDD) electrode. CVs indicate that the electro‐oxidation of both GA and EA are quasi‐reversible processes. High‐performance liquid chromatography (HPLC) coupled with a BDD electrode poised at+1.4 V offers the limit of detection (LOD, S/N=3) of 60 and 200 nM for GA and EA, respectively. The optimized method was then applied to the detection of both acids in Islay, Highland and Scotch whiskeys, with the highest concentrations found in a 14‐year‐old Highland whiskey.

Electrochemical determination of norepinephrine by adsorptive stripping voltammetry using a bare boron-doped diamond electrode

Electrochemical determination of norepinephrine by adsorptive stripping voltammetry using a bare boron-doped diamond electrode

Simultaneous Detection of Carbamates and Organophosphate Pesticides at Bare Boron-Doped Diamond Electrodes

Carbamate and organophosphate compounds are widely used pesticides because of their high insecticidal activity, and sometimes as nerve agents because of their crippling inhibition of the enzyme acetylcholinesterase (AChE)1. These compounds accumulate in the food chain and can hijack the nervous system of the target organisms indiscriminately. Traditional electrochemical methods of pesticide detection rely on layered structures atop noble metal or carbon electrodes to assist the loading of AChE, which produces currents proportional to its inhibition level. One of the clear advantages of boron-doped diamond (BDD) as an electrode material is its greater potential window in aqueous solutions, compared to conventional electrode materials2. This allows redox behaviour at extended potentials to be observed without damage to the electrode. Cyclic, differential-pulse, and square-wave voltammetric techniques were used to probe carbaryl (CB), carbofuran (CF), and malathion in Carmody buffers of pH 2–12. Oxidation of CF occurred at the three overpotentials 1.31 V, 1.44 V, and 1.69 V, and a broad reduction peak was observed at 1.10 V, referred against Ag|AgCl. Compared with the oxidation of CB at 1.35 V, these electrochemical differences allowed for simultaneous detection of both compounds. This non-enzymatic sensor demonstrated a linear calibration over a concentration range of 1–100 µM for CB (R=0.9834) and CF (R=0.9938). After exposure to 1 mM malathion, a reduction peak appears that is highly sensitive to pH, attributed to a complex carbon–oxygen adsorbate that is robust to aggressive cleaning methods and only removable by hydrogen plasma etching. This malathion modified surface may be advantageous in future applications such as pH sensing. The oxidised BDD demonstrated failsafe reproducibility, a linear response, and low detection limits at medically relevant concentrations. References Kostelnik, P. Kopel, A. Cegan, M. Pohanka, Sensors, 17 (2017) 676.V. Macpherson, Phys. Chem. Chem. Phys., 17 (2015) 2935-2949.

Controlled Electrochemical Synthesis of Ag Nanoparticles and Their Morphology-Dependent Performances on Catalysing Hydrogen Evolution Reactions

Hydrogen evolution reaction (HER) is one of the most critical reactions in fuel chemistry to produce clean and sustainable hydrogen gas as a renewable energy source. Nowadays, HER has always been catalysed with costly Pt or Pd metal1. To reduce the cost but still maintain a satisfactory performance, studies on Pt/Pd free catalysts for HER have never ceased. In the present work, we explore the electrodeposition of three morphologies (polyhedral, dendritic, and spherical) of Ag nanoparticles on boron-doped diamond electrodes (BDDEs) in various electrochemical conditions including deposition potential and deposition time. Specifically, by varying the deposition potentials of the single-stepped electrochemical deposition, a morphological change from polyhedral to homogeneous dendritic Ag was observed. The high deposition potential would drive the formation of dendritic Ag, which is a thermodynamically unfavourable structure with high surface energy. On the other hand, a two-stepped deposition mechanism was performed to synthesize spherical Ag nanoparticles. This two-stepped mechanism, which was used in synthesising small Au nanoparticles with high coverage by F. Bottari et al., contains a nucleation step at a more negative potential, and a growth step at a less negative potential.2 The sizes of each type of Ag nanoparticles were confirmed by Scanning Electron Microscopy (SEM), and the surface compositions were verified by X-Ray Photoelectron Spectroscopy (XPS). The current densities for HER catalysis were investigated using Linear Sweep Voltammetry (LSV), and a connection between morphologies and catalytic activities was drawn. All three types of Ag modified BDDEs showed better catalytic performance compared to that of drop-coated colloidal Ag-BDDE with comparable coverage and bare BDDE. Notably, spherical Ag-NP modified BDDE with an average particle diameter of 75nm has the highest percentage of pure elemental silver and showed the best performance as well as high stability in HER catalysis, which can be a less expensive yet efficient alternative for Pt/Pd containing catalysts.

BDD electrodes modified with metal nano-catalysts for coffee discrimination in real samples

An amperometric sensory approach based on boron-doped diamond (BDD) electrodes decorated with transition metals nano-catalysts was assessed for coffee discrimination in real samples. Thus, a bare BDD electrode along with four BDD electrodes modified respectively with Platinum/Iridium (PtIr), Platinum/Gold (PtAu), Gold/Ruthenium (AuRu) and Ruthenium (Ru) were investigated altogether in a broadly selective electrode array configuration to detect electro-active species in coffee samples. The transition metal nanoparticles were deposited onto BDD by sputtering thin metal layers onto polycrystalline BDD by a physical vapor deposition method, followed by a heat treatment at 700 °C under oxygen-free atmosphere. Such as process led to stable populations of strongly adherent nanosized metal particles over BDD surfaces as characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry. Chemometric analysis was adopted to examine the relevant parameters of the amperometric detection for classifying four coffee capsule samples. Promising results were obtained towards a new sensor technology to artificially predict taste for foodstuff analysis.

Voltammetric determination of plant hormone indole-3-butyric acid in acidic media employing boron-doped diamond electrode

Simple voltammetric approach, based on differential pulse voltammetry in combination with boron-doped diamond electrode (BDDE) as a sensor, was developed for rapid and precise determination of indole-3-butyric acid (IBA). The proposed method was based on the knowledge of IBA behavior in the acidic media, which was examined by nuclear magnetic resonance and mass spectrometry. Two distinctive products were identified. Therefore, one voltammetric “double signal” belonging probably to the oxidation of the IBA transformation products was recorded on a bare BDDE in medium of 0.6 mol dm−3 H2SO4. Parameters of differential pulse voltammetry were optimized and under the found conditions, it was reached good sensitivity, which enabled monitoring of phytohormones level in synthetic growth stimulators with sufficient results.

Voltammetric determination of leucovorin in pharmaceutical preparations using a boron-doped diamond electrode

Method for voltammetric determination of leucovorin, a drug frequently applied to decrease some unfavorable effects of anticancer drugs such as methotrexate or to increase the therapeutic effect of 5-fluorouracil, has been developed employing a bare boron-doped diamond electrode. It is the first method for leucovorin determination based on its electrochemical oxidation. Although at least three anodic and three cathodic voltammetric peaks could be recorded under the used conditions, only the anodic response situated at about + 900 mV (vs. saturated Ag|AgCl electrode) was suitable, namely due to its shape and position, for analytical purposes. Using differential pulse voltammetry with optimized parameters and supporting electrolyte of pH 3.0, the linear dynamic range of leucovorin determination was recorded from 0.15 to 25 μmol dm−3. Under such conditions, low limit of quantification of 0.050 μmol dm−3 and limit of detection of 0.015 μmol dm−3 as well was reached. Relative standard deviation calculated from 11 repeated measurements amounted to 0.7% and calculated from five repeated determinations amounting less than 3.0%. Applicability of the developed method was verified by repeated analysis of the pharmaceutical preparation with excellent results (recovery 98.7–102.8%, relative standard deviation 1.81%).

An advanced approach for electrochemical sensing of ibuprofen in pharmaceuticals and human urine samples using a bare boron-doped diamond electrode

Herein, an advanced electroanalytical approach for the determination of ibuprofen based on the use of a bare and electrochemically untreated boron-doped diamond electrode is presented. Cyclic voltammetric study revealed that the electrode reaction of the analyte was manifested by the presence of well-shaped irreversible and diffusion-driven oxidation peak at very high potential (+1.75 V vs. Ag/AgCl/3 mol L−1 KCl reference electrode) in 1 mol L−1 perchloric acid. After optimization of experimental conditions, the peak current of ibuprofen was proportionally linear from 9.49 × 10−7 to 6.69 × 10−5 mol L−1 providing both differential pulse (DPV) and square-wave voltammetric (SWV) techniques, respectively. The elaborated electroanalytical protocol rendered low detection limits of 4.1 × 10−7 and 9.3 × 10−7 mol L−1 in association with favourable intra-day repeatability (relative standard deviation of 3.6 and 4.6%) using DPV and SWV procedures, respectively. The effect of interfering compounds such as ascorbic acid, dopamine, caffeine, uric acid and glucose on the current response of ibuprofen was explored in details. The usefulness of the proposed approach was verified in the analysis of a variety of commercial brands of pharmaceuticals and spiked human urine samples with the significant range of recovery percentages (for pharmaceuticals: 99.8–107.5% and 99.8–105.0% by DPV and SWV, for urine: 95–107% and 97–103% by DPV and SWV). Taking these features into account, the developed protocol may be exploited as a novel, simple and efficient tool in drug quality control analysis and analysis of biological samples. In addition, a bare and electrochemically untreated boron-doped diamond electrode may be applied as a progressive electrochemical sensor and helpful alternative to previously utilized electrochemical platforms in this field.

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.

Electrodeposition of gold nanoparticles on boron doped diamond electrodes for the enhanced reduction of small organic molecules

The performance of gold nanoparticles electrodeposited on boron doped diamond (BDD) electrodes was investigated in respect to the reduction of chloramphenicol (CAP), an antibiotic of the phenicols family. The chosen deposition protocol, three nucleation-growing pulses, shows a remarkable surface coverage, with an even distribution of average-sized gold particles (~50nm), and it was proven capable of generating a three-fold increase in the CAP reduction current. A calibration plot for CAP detection was obtained in the micromolar range (5–35μM) with good correlation coefficient (0.9959) and an improved sensitivity of 0.053μAμM−1mm−2 compared to the electrochemistry of CAP at a bare BDD electrode.

Electrochemical determination of cephalosporins using a bare boron-doped diamond electrode

The electrochemical oxidation of seven cephalosporins (ceftriaxone, cefotaxime, ceftazidime, cefadroxil, cefuroxime, cefaclor, cefalexin) was evaluated at high potential, using a bare boron-doped diamond electrode and the influence on the analytical response of the side chains was investigated. Based on the anodic oxidation of the cephalosporin nucleus, a simple and sensitive method was developed for the electrochemical detection of cefalexin by differential pulse voltammetry. After the optimization of the experimental conditions, a linear correlation was obtained between the peak height and the molar concentration of cefalexin in the range of 0.5 μM–700 μM, with a limit of detection of 34.74 ng mL−1. The anodic peak for cefalexin was evaluated in the presence of other cephalosporin molecules and of other common interferents. The developed method was applied to detection of cefalexin from real environmental, biomedical and pharmaceutical samples, with good results. The electrochemical oxidation of cephalosporins was successfully adapted for flow injection analyses, with sensitive and reproducible successive analyses of cefalexin, in different concentrations. The flow analyses allowed also the determination of the total amount of cephalosporins found in the sample.

Electrochemical and analytical performance of boron-doped diamond electrode for determination of ascorbic acid

AbstractThe electrochemical behavior and determination of ascorbic acid (AA) was investigated at a bare boron-doped diamond (BDD) electrode using cyclic and differential pulse voltammetry. The influence of pH of supporting electrolyte and scan rate on the current response of analyte was examined to select the suitable experimental conditions. It was found that AA provided one well-shaped irreversible and diffusioncontrolled oxidation peak at +0.87 V vs. Ag/AgCl in Britton-Robinson buffer pH 4.0. Applying differential pulse voltammetry, the peak current of AA was linearly proportional to its concentration from 5 × 10-6to 2 × 10-4mol L-1(R2= 0.999), with the limit of detection of 1.1 × 10-6mol L-1and the good repeatability (relative standard deviation of 2.3 %). The developed electroanalytical protocol was successfully applied to determine the content of AA in commercial pharmaceutical preparations, based on the standard additions method, with the obtained recovery of 122 %. The accomplished analytical performance indicates that BDD electrodes are promising electrochemical sensors for pharmaceutical analysis.

Boron-doped diamond electrode acting as a voltammetric sensor for the detection of methomyl pesticide

Standard methods for the detection of carbamate pesticides are expensive, time-consuming, and require highly trained employees. Thus, electroanalytical methods are considered to be rapid, simple and low-cost alternatives. Here, we develop sensitive voltammetric methods for the determination of methomyl (a carbamate pesticide) using a bare boron-doped diamond electrode, square wave voltammetry (SWV), differential pulse voltammetry (DPV) and Britton–Robinson buffer (pH2.0) as supporting electrolyte. Methomyl has three oxidation processes: meantime process P1 was chosen for the analytical determination due to its higher sensitivity in comparison with other processes. The detection limits and concentration ranges of the SWV and DPV methods were 1.9×10−5 and 1.2×10−6molL−1, and 6.6–42.0×10−5 to 5.0–410.0×10−6molL−1, respectively. The proposed methods were successfully applied in river water, tap water and commercial formulations showcasing >80% mean recoveries. Comparing the two techniques, DPV was seen as the most sensitive method.

Electrochemical determination of resveratrol in dietary supplements at a boron-doped diamond electrode in the presence of hexadecyltrimethylammonium bromide using square-wave adsorptive stripping voltammetry

A sensitive electroanalytical methodology for the determination of resveratrol is presented for the first time using adsorptive stripping voltammetry at a bare boron-doped diamond (BDD) electrode. In cyclic voltammetry, resveratrol shows one irreversible and an adsorption-controlled oxidation peak at a BDD electrode. The voltammetric results indicated that in the presence of hexadecyl trimethyl ammonium bromide, the BDD electrode remarkably enhanced the oxidation of resveratrol, which leads to an improvement in the peak current with a shift of the peak potential to more positive values. Using the square-wave stripping mode, the compound yielded a well-defined voltammetric response in 0.1 M nitric acid solution containing 100 ?mol L-1 hexadecyl trimethyl ammonium bromide at 0.74 V (vs. Ag/AgCl), after 60 s accumulation at the open-circuit condition. A linear calibration graph was obtained in the concentration range 0.025 to 60.0 ?g mL-1, with a detection limit of 0.0063 ?g mL-1. The applicability of the proposed method was verified by analysis of resveratrol in commercial dietary supplements.