Voltammetric Methods Research Articles

Analysis of catechol as an environmental pollutant based on electropolymerised methyl orange modified carbon paste sensor

ABSTRACT The present research work outlines a low-cost and green electrochemical approach for the assay of ecological toxin catechol (CT) based on electro-polymerised methyl orange (MO)-activated carbon paste electrode (CPE) as a responsive, simple and low-priced electrocatalyst. The CT electrochemical response was premeditated on the surface of poly methyl orange-activated carbon paste electrode (Poly(MO)ACPE) using different voltammetric methods such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) which recommends that the Poly(MO)ACPE shows good electrocatalytic nature for the electrochemical redox reaction of CT with high peak current response as associated to the bare carbon paste electrode (BCPE). The CT molecules expose electrochemical quasi-reversible reactions (oxidation and reduction nature) at Poly(MO)ACPE, which was done by a diffusion-controlled reaction kinetics. The practicability of this sensor was verified using the DPV method; here the CT peak current was improved with the varied concentration of CT in the range from 1.0 µM to 36.0 µM, and the corresponding limit of detection (LOD) and limit of quantification (LOQ) were 0.880 × 10−8 M and 2.935 × 10−8 M, respectively. The prepared sensor was efficiently tested with different interferents using the DPV method. Here, the sensor shows a lesser interference effect for the CT redox reaction nature. Finally, this sensor was applied for the analysis of CT in water and green tea samples, and the outcomes noticed a good CT recoveries.

Some progress in voltammetric methods to detect malachite green in real samples using carbon electrodes

Carbon electrode materials have generated considerable research interest in recent years due to their ease of use, higher charge transfer kinetics, and cost-effectiveness. Malachite green (MG) is an organic compound with metallic-looking powdered green crystals, which got its name from the color of malachite. MG can be easily converted to leuco-malachite green, a colorless form (LMG). Because both MG forms are dangerous for human health, detecting them in the environment is important. Many researchers across the globe worked on MG detection using various techniques, and this article provides brief information on their results. In this review article, some specific information about electrochemical detection techniques, which are frequently employed for MG determination, is discussed. This review highlights some advances in voltammetric methods using carbon-based electrodes such as glassy carbon, carbon paste, pencil graphite, and their chemically modified forms in various configurations that can be used for the electrochemical detection of MG. Some of the future scopes in using these advanced, carbon-based electrodes in MG determination are also discussed.

Inclusion complexation of biphenyl-3,3′,4,4′-tetraamine and 4,4′-diaminobiphenyl-3,3′-diol with β-cyclodextrin for antibacterial activity

Inclusion complex (IC) of β-cyclodextrin (β-CD) with biphenyl-3,3′,4,4′-tetraamine (BPT), and 4,4′-diaminobiphenyl-3,3′-diol (DABD) are prepared and investigated in both solution and solid state. The effect of β-CD on the enhancement of solubility, stability, and antibacterial activity of poorly water-soluble BPT and DABD. Ultraviolet (UV), Fluorescence (FL), and Cyclic Voltammetric (CV) methods are particularly useful for determining stoichiometric ratios and binding constants in liquids. The prepared solid-phase ICs between host and guest are confirmed by powder XRD, SEM, DTA, FT-IR, and 1HNMR results. These results revealed that both BPT and DABD molecules formed ICs with β-CD with the stoichiometric ratio of 1:1.In this case, structurally confirmed ICs are required for investigating antibacterial activity, and their biological properties are as expected. It is widely acknowledged that these ICs recommended to the pharmaceutical and food industry due to their effective solubility, stability, and antibacterial activity.

CuONPs/MWCNTs/carbon paste modified electrode for determination of tramadol: theoretical and experimental investigation

A practical technique was applied to fabricate CuO nanostructures for use as the electrocatalyst. The green synthesis of cupric oxide nanoparticles (CuO NPs) via co-precipitation is described in this paper using an aqueous extract of Origanum majorana as both reductant and stabilizer, accompanied by characterization via XRD, SEM, and FTIR. The XRD pattern revealed no impurities, whereas SEM revealed low agglomerated spherical particles. CuO nanoparticles and multi wall carbon nanotubes (MWCNTs) have been used to create a modified carbon paste electrode. Voltammetric methods were used to analyze Tramadol using CuONPs/MWCNT as a working electrode. The produced nanocomposite showed high selectivity for Tramadol analysis with peak potentials of ~ 230 mV and ~ 700 mV and Excellent linear calibration curves for Tramadol ranging from 0.08 to 500.0 µM with a correlation coefficient of 0.9997 and detection limits of 0.025. Also, the CuO NPs/MWCNT/CPE sensor shows an an appreciable sensitivity of 0.0773 μA/μM to tramadol. For the first time the B3LYP/LanL2DZ, quantum method was used to compute DFT to determine nanocomposites' connected energy and bandgap energy. Eventually, CuO NPs/CNT was shown to be effective in detecting Tramadol in actual samples, with a recovery rate ranging from 96 to 104.3%.

Polymer-based Electrochemical Sensor: Fast, Accurate, and Simple Insulin Diagnostics Tool

Study of the use of polymers with higher conductivity like polypyrrole, and polyaniline in the electrochemical insulin sensors can overcome the drawbacks arising from the ongoing use of non-conductive polymer membrane. Conductive polymer membranes maintain the positive properties of polymers, like improved stability, reproducibility, and even increase the current response of the prepared sensor toward insulin oxidation. Three different screen-printed electrodes modified with polyaniline, polypyrrole, or chitosan with electrochemically deposited nickel nanoparticles ensuring insulin oxidation were prepared. The electrode morphology was examined via SEM with EDX analysis. Also, the electroactive surface area and stability were determined by voltammetric methods. Based on the results, the SPCEs modified by polypyrrole and nickel nanoparticles were determined as the most appropriate for the insulin determination. The NiNPs-PPy-SPCE exhibited a linear range (500 nM–5 µM), a low-down limit of detection (38 nM), high sensitivity (3.98 µA/µM), and excellent result from insulin determination in real samples (human blood serum). The results confirmed the high potential of developed sensor for future research focused on detection of insulin via electrochemistry methods in clinical samples.Graphical

Anode Process on Platinum in Low Temperature KF-AlF3-Al2O3 Based Melts: An Update

The present paper is devoted to obtaining new fundamental data on the electrochemical behavior of oxygen-evolving anodes in fluoride-oxide melts. In this work, the function of platinum and basics of its anode behavior as an ideal oxygen-releasing anode during electrolysis of the low temperature KF-AlF3-Al2O3 based melt were studied by potentiometric, cyclic voltammetric, and chronopotentiometric methods. The influence of the electrolyte composition, temperature, atmosphere, potential sweep rate, current density on the kinetics of the anode process was investigated. In order to clarify the mechanism of the process under study, electrolysis testing was carried out to inform an analysis of platinum oxidation products. Based on the experimental results, the validity of an earlier proposed scheme of the anode process on platinum when carrying out electrolysis of low temperature KF-AlF3-Al2O3 based melts was confirmed. Results will be used for theoretical modeling and studying the kinetics of the anode process on an over oxygen-evolving anodes in the fluoride-oxide melts.

A new tool for the determination of humic substances in natural waters: Pulsed voltammetry approach

Humic substances (HS) in natural waters can be determined with a new, simple and sensitive method based on their influence on the background current in a differential pulse - adsorptive cathodic stripping voltammetry. The proposed method, termed PB-HS (pulsed background - humic substances) is discussed in detail, including its application in natural samples from the Krka River estuary. The method was additionally compared with absorbance measurements as well as with the typical electrochemical HS quantification in natural waters based on HS complexation with molybdenum (Mo). A good correlation between methods was observed, with PB-HS showing slightly better sensitivity to humic compounds than classical spectrophotometry. Higher HS concentrations measured with the Mo-method may be due to the enhanced hydrophobicity reached at pH 2 that is required by the method. Advantages of the proposed PB-HS method, compared to existing voltammetric methods for HS quantification, are that it does not require any reagent addition (except buffer) and that it can be used at the natural pH of water as well as in a wide salinity range, which is crucial for its application in estuarine waters.

Optical and Electrochemical Sensing of Co(II), Ni(II) and Cu(II) in DMSO. Pyridyl Thiazole and (Thio)Amide Pincer Ligands versus Di‐2‐pyridyl Ketone Hydrazones

AbstractThe ability of six pincer type molecules (di‐2‐pyridyl ketone acetic acid hydrazone (1), N‐(2,5‐dimethoxyphenyl)‐6‐[(2,5‐dimethoxyphenyl)carbamothioyl]pyridine‐2‐carboxamide (2), 6‐(4,7‐dimethoxy‐2‐benzothiazolyl)‐N‐(2,5‐dimethoxyphenyl)‐2‐pyridinecarboxamide (3), di‐2‐pyridyl ketone thiosemicarbazone (4), bis‐N‐(2,5‐dimethoxyphenyl)pyridine‐2,6‐dicarbothioamide (5), and 6‐(4,7‐dimethoxy‐2‐benzothiazolyl)‐N‐(2,5‐dimethoxyphenyl)‐2‐pyridinecarbothioamide (6)), to detect MBr2 (where M=Co, Ni, and Cu) in DMSO was quantified via formation constants determined from spectrophotometric and voltammetric titrations. The limit of detection (from electronic spectroscopy) of 1–6 ranged from 0.9‐9.5 ppm. The values of β (=log K) for the six species were found to be in the ranges of 4.3–4.9 and 4.0–6.3 for Co(II), 3.9–5.5 and 3.5–4.3 for Ni(II), and 4.0–4.3 and 3.7–5.0 for Cu(II) by UV‐visible and voltammetric methods, respectively. The results suggested that κ3‐NNS (6) and the κ3‐NNO (3) had good affinity for Ni(II) and Cu(II), whereas the κ3‐SNS (5) had greater affinities for Co(II) and Ni(II). The hydrazones (κ3‐NNO, 1 and κ3‐NNS, 4) were generally in the middle of the pack, displaying good affinity for the three metal ions. In a contrasting vein, the κ3‐ONS species (2) was generally the lowest across the pincers. DFT calculations (PBE0/6‐31G(d,p)/SMD) suggested that stable complexes of coordination numbers=4 to 6 were plausible in solution.

Effect of Plants Morphological Parameters on Plant-Microbial Fuel Cell Efficiency

Background. Plant-microbial fuel cell (PMFC) is an innovative biotechnology for the environmentally safe bioelectricity generation. The widespread use of bioelectrical systems (biosystems) is hindered by their insufficient efficiency due to limiting knowings of the relationship between bioelectricity generation and features of their biotechnological components. Objective. Тhe purpose of this study was to analyze the role of the plants morphological parameters and structure features of biomodules on generation of bioelectricity. Methods. Biometric, biogravimetric, voltammetric, and statistical analysis methods were used to assess the relationship between plant`s accumulated mass of leaf and roots, multielectrode design of biosystem and bioelectricity generation. Results. PMFC based on sedge C. hirta with the largest accumulated total dry leaf/stem and root mass and also the rhizome-like and developed fibrous root system were characterized by the highest power output compared to other biosystems. The power density was 970 ± 22 mW m-2 PGA. The parallel stacking of biomodules leads to obtain current output about 108.7 mA. That is why the developed biotechnological systems can be recommended as a foundation for the development of power supply for WiFi microcontrollers that consume 100 mA or for charging batteries. Conclusions. Sedge С. hirta were appeared as the more suitable plants for biological component of biosystem of bioelectricity generation. Power density of С. hirta based PMFC exceeded the one of based on other plants in 9.3–37.9%.The type and level of development of the root system and of the above-ground photosynthetic surface of plant are an important prognostic factors of the PMFC perfomance. A 10-fold increase of the electrode surface of one biomodule results in 3.95 times increase of power density at 200 W. The multielectrodeity biomodule reveals as another lever for increasing the efficiency of biosystems which allows obtaining significantly increase power density and current density in the range of electrical resistance from 50 to 500 W.

Intracranial subsecond dopamine measurements during a "sure bet or gamble" decision-making task in patients with alcohol use disorder suggest diminished dopaminergic signals about relief.

To the authors' knowledge, no data have been reported on dopamine fluctuations on subsecond timescales in humans with alcohol use disorder (AUD). In this study, dopamine release was monitored in 2 patients with and 2 without a history of AUD during a "sure bet or gamble" (SBORG) decision-making task to begin to characterize how subsecond dopamine responses to counterfactual information, related to psychological notions of regret and relief, in AUD may be altered. Measurements of extracellular dopamine levels were made once every 100 msec using human voltammetric methods. Measurements were made in the caudate during deep brain stimulation electrode implantation surgeries (for treatment of movement disorders) in patients who did (AUD, n = 2) or did not (non-AUD, n = 2) have a history of AUD. Participants performed an SBORG decision-making task in which they made choices between sure bets and 50%-chance monetary gamble outcomes. Fast changes were found in dopamine levels that appear to be modulated by "what could have been" and by patients' AUD status. Positive counterfactual prediction errors (related to relief) differentiated patients with versus without a history of AUD. Dopaminergic encoding of counterfactual information appears to differ between patients with and without AUD. The current study has a major limitation of a limited sample size, but these data provide a rare insight into dopaminergic physiology during real-time decision-making in humans with an addiction disorder. The authors hope future work will expand the sample size and determine the generalizability of the current results.

Highly sensitive electrochemical sensor based on carbon paste electrode modified with graphene nanoribbon-CoFe2O4@NiO and ionic liquid for azithromycin antibiotic monitoring in biological and pharmaceutical samples.

In this report, Azithromycin (Azi) antibiotic was measured by carbon paste electrode (CPE) improved by graphene nanoribbon-CoFe2O4@NiO nanocomposite and 1-hexyl-3 methylimidazolium hexafluorophosphate (HMIM PF6) as an ionic liquid binder. The electrochemical behavior of Azi on the graphene nanoribbon-CoFe2O4@NiO/HMIM PF6/CPE is investigated by voltammetric methods, and the results showed that the modifiers improve the conductivity and electrochemical activity of the CPE. According to obtained data, the electrochemical behavior of Azi is related to pH. under optimum conditions, the sensor has linear ranges from 10µM to 2mM with a LOD of 0.66µM. The effect of scan rate and chronoamperometry were studied, which showed that the Azi electro-oxidation is diffusion controlled with the diffusion coefficient of 9.22 × 10-6 cm2/s. The reproducibility (3.15%), repeatability (2.5%), selectivity, and stability (for 30days) tests were investigated, which results were acceptable. The actual sample analysis confirmed that the proposed sensor is an appropriate electrochemical tool for Azi determination in urine and Azi capsule.

Ultrasensitive Electrochemical Sensor Based on SnO2 Anchored 3D Porous Reduced Graphene Oxide Nanostructure Produced via Sustainable Green Protocol for Subnanomolar Determination of Anti-Diabetic Drug, Repaglinide

Herein, we have reported on a simple, environmentally friendly, and ultra-sensitive electrode material, SnO2@p-rGO, used in a clean sustainable manner for rapid electrochemical determination of an anti-diabetic agent, repaglinide (RPG). Three-dimensional porous reduced graphene oxide nanostructure (p-rGO) was prepared via a low-temperature solution combustion method employing glycine. The aqueous extract of agricultural waste “cotton boll peel” served as stabilizing and reducing agents for the synthesis of SnO2 nanoparticles. The structural and morphological characterization was carried out by XRD, Raman, SEM, EDX, FTIR, absorption, and TGA. The oxidation process of RPG was realized under adsorption controlled with the involvement of two protons and electrons. The sensor displayed a wider linearity between the concentration of RPG and oxidation peak current in the ranges of 1.99 × 10−8–1.45 × 10−5 M and 4.99 × 10−8–1.83 × 10−5 M for square-wave voltammetric and differential pulse voltammetric methods, respectively. The lower limit of detection value of 0.85 × 10−9 M was realized with the SWV method. The proposed sensor was applied for the quantification of RPG in fortified urine samples and pharmaceutical formulations. Furthermore, the sensor demonstrated reproducibility, long-term stability, and selectivity in the presence of metformin and other interferents, which made the proposed sensor promising and superior for monitoring RPG.

A novel mesna-based electrochemical sensor embellished with silver nanoparticles for ultrasensitive analysis of modafinil.

Modafinil (MOD) is a CNS stimulant used for the treatment of narcolepsy, shift work sleep disorder, excessive daytime sleepiness, and post-COVID 19 neurological symptoms. In the literature, there is no report of square wave voltammetric (SWV) methods being used for the determination of MOD. This study describes, for the first time, the construction and evaluation of the analytical performance of a novel sensor for ultrasensitive SWV detection of MOD. The sensor was constructed by integration of silver nanoparticles (AgNPs) on Mesna (MSN) layers over a pencil graphite electrode (PGE) surface. The interface and morphological characteristics of the fabricated AgNPs@MSN/PGE sensor were investigated via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). This sensor was found to enhance the electro-oxidation of MOD. The combination of AgNPs@MSN/PGE with SWV enabled the determination of MOD in its bulk form and in pharmaceutical and biological matrices at the nanomolar scale (LOD = 28.59 nM) with excellent recoveries. This study represents the first report describing an electrochemical procedure for MOD detection in human plasma. The established SWV method was also validated, and the results were consistent with ICH criteria. Finally, the presented SWV procedure provides a facile, sensitive, rapid, and cost-effective approach compared to other existing methods.

Comparison of carbon paste and boron-doped diamond electrodes for determination of cefepime in pharmaceutical dosage forms and biological samples

The electrochemical analysis of cefepime, a fourth-generation cephalosporin, was investigated in the direction of oxidation using a carbon paste (CP) electrode and a boron-doped diamond (BDD) electrode. The optimum paste composition was determined as 25 % mineral oil-75 % graphite powder for the CP electrode. The effects of different pHs and scan rates on the anodic peak potential and peak current of cefepime were investigated. Scan rate studies were carried out in the range of 5–200 mV s −1 (vs. Ag/AgCl). It was found that the CP electrode had an adsorption-controlled process and the BDD electrode had a diffusion-controlled process under some adsorption effect. The linear ranges of cefepime obtained for the CP electrode were determined as 0.08–10 μM (correlation coefficient; r = 0.998) for differential pulse stripping voltammetry with a detection limit of 3.73 nM and 0.4–10 μM ( r = 0.998) for square wave stripping voltammetry with a detection limit of 22.1 nM. For the BDD electrode, cefepime gave a linear range of 0.04–10 μM ( r = 0.999) for differential pulse voltammetry with a detection limit of 1.58 nM and 0.4–60 μM ( r = 0.998) for square wave voltammetry with a detection limit 11.0 nM. The precision of the proposed methods was examined by repeatability studies and presented by relative standard deviation (RSD) values below 1.76 %. Quantitative analysis of cefepime from pharmaceutical dosage forms and human serum samples using the developed methods was performed for both electrodes without any separation or filtering pretreatment. Recoveries were between 99.41 and 102.07 % for pharmaceutical dosage forms and between 99.79 and 100.50 % for human serum samples, with RSD ranging from 0.70 % to 0.98 %. • Sensitive detection of cefepime helps to increase the effectiveness of treatment. • Side effects in the treatment can be reduced by the determination of cefepime. • Oxidative determination of cefepime can be done using non-toxic solid electrodes. • Carbon paste and boron doped diamond electrodes offer advantages over each other. • Voltammetric methods enable determination from serum samples without pretreatment.

Assessing the Food Quality Using Carbon Nanomaterial Based Electrodes by Voltammetric Techniques

The world is facing a global financial loss and health effects due to food quality adulteration and contamination, which are seriously affecting human health. Synthetic colors, flavors, and preservatives are added to make food more attractive to consumers. Therefore, food safety has become one of the fundamental needs of mankind. Due to the importance of food safety, the world is in great need of developing desirable and accurate methods for determining the quality of food. In recent years, the electrochemical methods have become more popular, due to their simplicity, ease in handling, economics, and specificity in determining food safety. Common food contaminants, such as pesticides, additives, and animal drug residues, cause foods that are most vulnerable to contamination to undergo evaluation frequently. The present review article discusses the electrochemical detection of the above food contaminants using different carbon nanomaterials, such as carbon nanotubes (CNTs), graphene, ordered mesoporous carbon (OMC), carbon dots, boron doped diamond (BDD), and fullerenes. The voltammetric methods, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV), have been proven to be potential methods for determining food contaminants. The use of carbon-based electrodes has the added advantage of electrochemically sensing the food contaminants due to their excellent sensitivity, specificity, large surface area, high porosity, antifouling, and biocompatibility.

Au–Ru Composite for Enzyme-Free Epinephrine Sensing

We report the synthesis and investigation of Au–Ru composite with highly developed specific surface area exhibiting excellent electrocatalytic performance suitable for detection of such hydrophobic metabolites as epinephrine in the physiological environment. This electrode material was fabricated using two-stage laser-assisted metal deposition technique. The morphological and structural studies of Au–Ru were performed using methods of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction spectroscopy (XRD). The voltammetric methods, including cyclic voltammetry (CV), differential pulse voltammetry (DPV) and direct amperometry, were used to analyze the composite’s electrochemical properties. The Au–Ru sensor exhibited two linear ranges of the non-enzymatic epinephrine detection: 0.01–10 μM and 10–1000 μM. The calculated sensitivities within these two ranges were 32.8 and 3.3 μA μM−1 cm−2, whereas the corresponding limits of detection were 9 and 20 nM, respectively. The Au–Ru sensor also revealed good stability and reproducibility, as well as high selectivity towards epinephrine detection in the presence of a number of the interfering species.

Advances on Hormones and Steroids Determination: A Review of Voltammetric Methods since 2000.

This article presents advances in the electrochemical determination of hormones and steroids since 2000. A wide spectrum of techniques and working electrodes have been involved in the reported measurements in order to obtain the lowest possible limits of detection. The voltammetric and polarographic techniques, due to their sensitivity and easiness, could be used as alternatives to other, more complicated, analytical assays. Still, growing interest in designing a new construction of the working electrodes enables us to prepare new measurement procedures and obtain lower limits of detection. A brief description of the measured compounds has been presented, along with a comparison of the obtained results.

Detection of Synthetic Antioxidants: What Factors Affect the Efficiency in the Chromatographic Analysis and in the Electrochemical Analysis?

Antioxidants are food additives largely employed to inhibit oxidative reactions in foodstuffs rich in oils and fat lipids, extending the shelf life of foodstuffs and inhibiting alterations in color, flavor, smell, and loss of nutritional value. However, various research has demonstrated that the inadequate use of synthetic antioxidants results in environmental and health problems due to the fact that some of these compounds present toxicity, and their presence in the human body, in high concentrations, is related to the development of some cancer types and other diseases. Therefore, the development of analytical methods for identifying and quantifying synthetic antioxidants in foodstuffs is fundamental to quality control and in ensuring consumer food safety. This review describes the recent chromatographic and electrochemical techniques used in the detection of synthetic phenolic antioxidants in foodstuffs, highlighting the main characteristics, advantages and disadvantages of these methods, and specific typical features, which include extraction methods for sample preparation and materials used in the working electrode construction, considering chromatographic and voltammetric methods, since these specific features influence the efficiency in the analysis.

Electrochemical Sensor Based on Ni-Co Layered Double Hydroxide Hollow Nanostructures for Ultrasensitive Detection of Sumatriptan and Naproxen.

In this work, Ni-Co layered double hydroxide (Ni–Co LDH) hollow nanostructures were synthesized and characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FT-IR) techniques. A screen-printed electrode (SPE) surface was modified with as-fabricated Ni–Co LDHs to achieve a new sensing platform for determination of sumatriptan. The electrochemical behavior of the Ni–Co LDH-modified SPE (Ni-CO LDH/SPE) for sumatriptan determination was investigated using voltammetric methods. Compared with bare SPE, the presence of Ni-Co LDH was effective in the enhancement of electron transport rate between the electrode and analyte, as well as in the significant reduction of the overpotential of sumatriptan oxidation. Differential pulse voltammetry (DPV) was applied to perform a quantitative analysis of sumatriptan. The linearity range was found to be between 0.01 and 435.0 μM. The limits of detection (LOD) and sensitivity were 0.002 ± 0.0001 μM and 0.1017 ± 0.0001 μA/μM, respectively. In addition, the performance of the Ni-CO LDH/SPE for the determination of sumatriptan in the presence of naproxen was studied. Simultaneous analysis of sumatriptan with naproxen showed well-separated peaks leading to a quick and selective analysis of sumatriptan. Furthermore, the practical applicability of the prepared Ni-CO LDH/SPE sensor was examined in pharmaceutical and biological samples with satisfactory recovery results.

Voltammetric analysis of serotonin and epinephrine in the presence of guanine and adenine at Bismarck brown R amplified pencil graphite electrode

Simultaneous resolution of SE and EP in of AD and GU by CV and DPV at PBBR-MGPE. • Bismarck brown R (BBR) was fabricated by electropolymerisation process. • Modified electrode exhibits excellent selectivity, sensitivity and stability. • Modified Graphite pencil electrode successfully implemented for the electranalysis of serotonin and epinephrine in assistant with adenine and guanine. • Cost effective, simple and applied in electrochemical monitoring. In present study, the novel sensing platform was electrochemically designed by incorporation of Bismarck brown R (BBR) as a enhancing substance onto the graphite pencil electrode(GPE) surface and successfully implemented for the electroanalysis of serotonin(SE) and epinephrine(EP) in assistant with adenine (AD) and guanine(GU) through cyclic and differential pulse voltammetric methods(CV and DPV). The morphology of electrode surface was characterised by scanning electron microscopy (SEM). The test solutions and operating conditions such as scan rate, varied supporting electrolyte pH and concentration of targeted analytes were optimised. The electrode kinetics of a tailored sensor was governed by both adsorption and diffusion phenomenon and gives a reduced detection limits for SE and EP respectively. The configured electrode proffers the potent and persistent specificity and sensibility followed by distinctly separated four anodic signals of SE, EP, AD and GU with appreciable increments in peak currents. Therefore, the offered sensor was cost effective, simple and applied in electrochemical monitoring and biosensing applications.