Modified Carbon Paste Electrode Research Articles

Amino‐Montmorillonite Crystalline Clay as Electrode Modifier for Electrochemical Detection of Ciprofloxacin in Presence of Cetyltrimethylammonium Bromide

AbstractThis research focused on harnessing amino‐functionalized montmorillonite (Mt) clay, achieved through the grafting of [3(2‐aminoethyl)amino]propyltrimethoxysilane (AEP‐TMS), as carbon paste electrode (CPE) modifier for the electroanalysis of ciprofloxacin (CF). The characterization of both Mt and the amino‐functionalized (Mt‐NH2) materials was carried out using various techniques including Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X‐ray diffraction (XRD). Afterwards, various CPEs modified using Mt and Mt‐NH2 were prepared and characterized employing SEM‐energy dispersive X‐ray (EDX), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). By EIS, Mt‐NH2‐CPE exhibited significantly faster electron transfer with lower charge‐transfer resistance (438.5 Ω) compared to Mt‐CPE (3572.1 Ω) and to the bare CPE (2066.1 Ω). Additionally, CV experiments performed by using redox probes demonstrated the excellent accumulation capability of [Fe(CN)6]3− ions on Mt‐NH2‐CPE surface. The Mt‐NH2‐CPE was subsequently applied using square wave voltammetry to determine CF in the presence of cetyltrimethylammonium bromide (CTAB), yielding an impressive linear range from 30 to 240 μM (R=0.999) and a low detection limit of 0.07 μM (23.2 μg L−1). The method exhibited stable and reproducible responses (RSD=3.25 %; n= 6) under optimized conditions. Following interference studies, the optimized method was effectively applied to quantify CF concentrations in pharmaceutical and water samples.

Modification of carbon paste electrodes for the selective determination of adenosine in the presence of phosphate adenylic derivatives

Modification of carbon paste electrodes for the selective determination of adenosine in the presence of phosphate adenylic derivatives

Ferulic acid detection in honey using carbon paste electrode modified by C-C3N4/Li2CoMn3O8 nanocomposite

Honey is regarded as a valuable food commodity which has many and varied components, including phenolic compounds. Ferulic acid (FA) is one of these compounds, which possesses activities such as antioxidant, anti-inflammatory, anti-diabetic, haemolytic, antiviral, anti-cancer, etc. In view of these unique characteristics, a quick, sensitive, simple and inexpensive method for FA identification is required. This research developed a novel electrochemical sensor for measuring FA in honey samples. The sensor utilizes a C-C3N4/Li2CoMn3O8 nanocomposite modified carbon paste electrode (C-C3N4/LCMO/CPE) to enhance the sensitivity and detection. The synthesized nanocomposite exhibits remarkable properties, featuring an abundance of electrochemically active sites and enhanced electron transfer rates, making it ideal for developing advanced electrochemical sensors. The XRD, SEM and EDX analysis were used to examine and look like the synthesised nanocomposite structure. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods were used to evaluate the electrochemical behavior of C-C3N4/LCMO/CPE sensor for FA detection and optimized by adjusting pH, and potential scan rate. FA was measured in a phosphate buffered saline (PBS; 0.1 M, pH 4.0) by DPV with the detection limit of 3.6 nM and quantitative limit of 0.009 µM in the linear response ranges of 0.009–3.000 and 5.00–100 µM. Chronoamperometry was utilized to calculate the diffusion coefficient of FA (D = 3.45 (±0.11) × 10−6 cm2.s−1) on the surface of the C-C3N4/LCMO/CPE, as well as the electron transfer coefficient (α = 0.68). The sensor’s high sensitivity for accurately assessing FA in real samples was demonstrated by recovery values ranging from 96.96 to 102.36 %.

A new sensing platform based on poly(valine)-modified carbon paste electrode for the determination of hydroquinone and resorcinol

A new sensing platform based on poly(valine)-modified carbon paste electrode for the determination of hydroquinone and resorcinol

Green voltammetric method for determination of diclofenac sodium in environmental and biological samples using aluminium tungstate nanoparticles modified carbon paste electrode

ABSTRACT Based upon aluminium tungstate (Al2(WO4)3 NPs), a new modified sensor was created in order to monitor diclofenac sodium (DCF) electrochemically in environmental samples. The electrode composition, electrolyte effect, selectivity, scan rate, and pH parameters that affect the assay’s performance were optimised and the pH study revealed that pH 3.6 was found to be suitable to improve the electrochemical behaviour of diclofenac. The electrochemical characteristics of the built-in electrode were assessed using cyclic voltammetry technique (CV).The electrode composition, electrolyte effect, selectivity, scan rate, and pH parameters were optimised. The limit of detection was found to be 0.076 µM and the limit of quantification (LOQ) value was 0.25 µM for the concentration range (0.2–25 µM) of DCF. It has demonstrated good selectivity for (DCF) in presence of the interfering species and its electrochemical sensing’s repeatability, reproducibility and stability were evaluated and found typical. Some environmental samples like tap water, waste water, Nile-river water and biological ones like urine and plasma, have been effectively applied using the proposed electrochemical sensor. Green chemistry metrics, viz. Analytical GREEnness Preparation (AGREEprep), Analytical Eco-Scale Assessments (ESA) and The AMVI for the proposed method were calculated and have assured that the method has limited negative impact on both human health and the environment.

Synthesis of graphitic carbon nitride (g-C3N4) by high-temperature condensation for electrochemical evaluation of dichlorophen and thymol in environmental trials

The work deals with synthesizing carbon-based nanomaterial, i.e., graphitic carbon nitride, which was carried out using the high-temperature condensation method. Graphitic carbon nitride is characterized by cost efficiency, increased thermal resilience, a two-dimensional molecular layer structure, biocompatibility and stability. These properties can be used in the electrochemical investigations of fungicides such as dichlorophen and thymol. The synthesized nanomaterial was first characterized using XRD, SEM, UV-DRS, BET, FTIR, CV and EIS investigations. The cyclic voltammetry behavior of dichlorophen and thymol shows the proton-coupled irreversible electron transfer process at a modified carbon paste electrode with the participation of same number of protons and electrons. The developed sensor exhibited good detection limits for the dichlorophen and thymol as low as 15.3 nM and 12.0 nM with the sensitivity of 126.8 µA·µM−1·cm−2 and 59.2 µA·µM−1·cm−2, respectively. The applicability of the developed sensor was tested in spiked soil and water samples, and good recoveries were achieved with a% RSD of 1.67 and 1.30, respectively. The anti-interference responses to metal ions demonstrate the selectivity (qualitative) of the developed sensor in the electrochemical detection of dichlorophen and thymol. In the future, the sensor developed would offer the potential to sensitively and selectively detect other pesticide molecules in environmental samples.

Electrochemical and quantum chemical approaches to the study of dopamine sensing using bentonite and l-cysteine modified carbon paste electrode

This work presents a significant investigation involving both electrochemical experiment and quantum chemical simulation approaches. The objective was to characterize the electrochemical detection of dopamine (DA). The detection was carried out using a modified carbon paste electrode (CPE) incorporating bentonite (Bent) and l-cysteine (CySH) (named as CySH/Bent/CPE). To understand and explain the oxidation mechanism of DA on the CySH/Bent modified electrode surface, the coupling of the two approaches were exploited. The CySH/Bent/CPE showed excellent electroactivity toward DA such as good sensibility, selectivity, stability, and regenerative ability. The developed sensor shows a dynamic linear range from 0.8 to 80 μM with a limit of detection and quantification of 0.5 μM and 1.5 μM, respectively. During the quantitative analysis of DA in presence of ascorbic acid (AA) and uric acid (UA) the electrochemical oxidation signals of AA, DA, and UA distinctly appear as three separate peaks. The potential differences between the peaks are 190 mv, 150 mv, and 340 mV for the AA–DA, DA–UA, and AA–UA oxidation pairs, respectively. These observations stem from square wave voltammetry (SWV) studies, along with the corresponding redox peak potential separations. The developed sensor is simple and accurate to monitor DA in human serum samples. On the other hand, CySH acts as an electrocatalyst on the CySH/Bent/CPE surface by increasing its active electron transfer sites, as suggested by the quantum chemical modeling with analytical results of Fukui. Furthermore, the voltammetric results obtained agree well with the theoretical calculations.

Role of electron transfer between bare electrode and benzoguanamine to fabricate an electrochemical sensor for drugs: Theoretical and electrochemical approach

Herein, a poly(benzoguanamine) (BNZ) modified carbon paste electrode (CPE) was applied for the electroanalysis of paracetamol (PA) in PA tablet and human urine. Theoretical evaluation of the quantum chemical parameters of benzoguanamine (BZ) via density functional theory (DFT) calculations show that it is a reactive monomer with a tendency for back bond formation with the bare carbon paste electrode (BCPE). Scanning electron microscopy (SEM) images of BCPE and BNZ modified CPE (BNZ/CPE) show that the BNZ films were deposited on the bare electrode in layers. Results of the electrochemical characterization of these electrodes in 1 mM K4[Fe(CN)6] revealed that the BNZ/CPE has a higher electrocatalytic activity towards K4[Fe(CN)6] oxidation than BCPE. The limit of detection (LOD) of PA at the BNZ/CPE was estimated as 13.2 nM over a linear dynamic range (LDR) of 0.05–0.45 μM. Also, the proposed sensor offered PA recoveries of 99.2–100.4 % and 98.4–100.8 % in PA tablet solution and human urine sample, respectively. The BNZ/CPE showed remarkable shelf-life by retaining 97.4 % of its initial current response after 21 days of application for PA electroanalysis at 7 days interval. Notably, this study is the first attempt at the application of the BNZ/CPE for PA electroanalysis.

Copper @ eggshell nanocomposite/chitosan gelified carbon paste electrode as an electrochemical biosensor for l-tyrosine analysis as a biomarker in the serum of normal and liver disease patients

L-Tyrosine (L-Tyr), an amino acid, has emerged as a potential biomarker for the detection and monitoring of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). By analysing the serum levels of L-Tyr, healthcare professionals can gain insights into the progression and development of these liver diseases. The utilization of L-Tyr as a biomarker holds potential for early detection and timely intervention, improving patient outcomes and treatment options. In this study we developed a novel nanocomposite based on eggshell waste and copper nanoparticles to modify carbon paste electrode (CPE) using chitosan gel as a binder for sensitive estimation of L-Tyr in human serum samples. The use of chitosan gel avoids the insulating effect of paraffin oil that was usually used for fabrication of CPE and enhance the sensitivity and selectivity of the modified electrode. Square wave voltammetry (SWV) was used to optimize the electrochemical parameters of the oxidation of L-Tyr onto the surface of the fabricated electrode (CuNPs@ESh/CS/CPE). The prepared composite was characterized using X-ray diffraction (XRD), Fourier Transform − Infrared spectroscopy (FT-IR), UV–VIS spectroscopy and scan electron microscopy (SEM) and electrochemical impedence spectroscopy (EIS). The fabricated biosensor could estimate L-Tyr levels in controls, LC and HCC patients’ serum with high accuracy and sensitivity. The obtained results demonstrated the presence of significant difference in L-Tyr levels in the three studied groups. This indicates that L-Tyr amino acid may serve as a crucial biomarker for the evaluation of such liver diseases.

Eco-friendly synthesis of cluster-like Dy2Ce2O7 nanoparticles using orange juice and their application in electrochemical determination of isoniazid

In this study, cluster-like (CL) Dy2Ce2O7 nanoparticles were synthesized via an easy and rapid sonochemical pathway. X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) were used for the characterization of nanoparticles. The construction of an electrochemical sensor was performed to determine isoniazid (IZN) based on ionic liquid (IL) and the cluster-like nanostructure of Dy2Ce2O7 modified carbon paste electrode (CL-Dy2Ce2O7/IL/CPE). Using the fabricated sensor, cyclic voltammetry (CV) along with differential pulse voltammetry (DPV) have been utilized to examine the catalytic activity of the modified electrode toward oxidation of IZN in 0.1 M phosphate buffer solution (PBS) with pH of 7.0. The large specific surface area and electrocatalytic properties of CL-Dy2Ce2O7 as well as the good electrical conductivity of ionic liquid greatly enhanced the current signal of the IZN at the CL-Dy2Ce2O7/IL/CPE. The process at the surface of the electrode was under the diffusion control mechanism and the diffusion coefficient for IZN was 1.08 × 10−5 cm2/s. Additionally, with a low detection limit of 9.0 nM, the peak current of IZN rose linearly with concentration in the range of 0.02–340.0 μM. Our findings demonstrate that the sensitive and selective detection of IZN in pharmaceutical and biological samples can be achieved using the CL-Dy2Ce2O7/IL/CPE.

Electrochemical determination of uric acid in presence of folic acid using synthesized cobalt oxide modified carbon paste electrode

Here, the synthesis of CoO nanoparticle by using co-precipitation method and characterized by XRD, SEM and EDAX techniques. The CoO nanoparticle used as modified carbon paste electrode for sensing the UA in presence of FA. The CoO/MCPE shows the excellence sensitivity towards the determination of both UA and FA. The kinetic electron transfer study of UA and FA shows with good linearity and both electrodes showed adsorption electrode process. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 3.32 µM and 11.1 µM for FA and 6.09 µM and 20.3 µM for UA, respectively. The CoO/MCPE applied for the simultaneous electrochemical determination of UA and FA, the proposed method was used for real sample analysis.

Sr and Fe substituted LaCoO3 nano perovskites: Electrochemical energy storage and sensing applications

Perovskite-type LaCoO3 (LCO), La0.8Sr0.2CoO3 (LSCO), and La0.8Sr0.2Co0.9Fe0.1O3 (LSCFO) were prepared though a sol gel assisted hydrothermal method for supercapacitors and electrochemical sensors for heavy metal ions detection applications. Rhombohedral crystal structure was confirmed using experimental and DFT based computational XRD pattern. LCO, LSCO and LSCFO based modified carbon paste electrodes were prepared for cyclic voltammetry, electrochemical impedance spectra and galvanostatic charge discharge measurements. Among all electrodes, LSCFO results with 715.5 Fg−1 specific capacitance with 97 % retention after 1500 cycles. Cyclic voltammetry measurements for the sensing and detection of heavy metal ions (chromium and mercury) were carried out using all three electrodes and observed that LSCFO showed better response comparatively to that of other two electrodes, thus can be claimed as a potential mixed metal oxide nanomaterial for the fabrication of electrodes for storage of energy and sensor applications.

Electrochemically polymerized dopamine activated carbon paste sensor for selective and sensitive detection of rutin in the presence of riboflavin

In this work, a sensor was developed for the quantification of RT in food and medicine samples using electro-polymerization of dopamine (DA) on the surface of a carbon paste electrode in 0.2 M phosphate buffered saline (PBS) of 7.0 pH by cyclic voltammetry (CV). The surface properties of bare carbon paste electrode (BCPE) and poly (DA) modified carbon paste electrode (PDAMCPE) were studied using scanning electron microscopy (SEM), electrochemical impedance study (EIS), and CV techniques. Two electron two proton transfer process was seen during the electrochemical reaction of RT with adsorption-controlled process. Under optimum conditions, the peak current increased linearly with an increase in RT concentration for CV in the range of 0.4 to 2.0 μM and differential pulse voltammetry (DPV) in the range of 0.4 to 2.5 μM and the limit of detection (LOD) was found to be 0.0045 μΜ and for CV and 0.079 μM for DPV techniques respectively. Even in the presence of some interferents like organic compounds and metal ions, the developed electrode exhibits good anti-interference ability for RT, and good selectivity was obtained for RT in the presence of riboflavin (RF). The developed sensor presents good stability, repeatability, and reproducibility. The CV measurement was performed for the analysis of RT in real samples such as green tea and medicine samples which showed a good recovery and this work has been not reported previously.

Fabrication of mechanically alloyed high entropy alloys (20-Fe-20Cr-20Ni-20Mn-20Ti) modified carbon paste electrode sensor for the cyclic voltammetric determination of methyl orange

We have successfully fabricated high entropy alloys (HEA) of composition 20-Fe-20Cr-20Ni-20Mn-20Ti by ball milling method for 20 h after optimizing the milling parameters. Generally, the HEAs are very popular for their multi-elemental cocktail effect and exhibit excellent high temperature oxidation resistance, high strength, electromagnetic, wear and corrosion resistance properties. But, HEAs also exhibit significant electrocatalytic properties due to their unique morphology, composition, and structure. Therefore, we have used planetary ball milled HEA powders for the electrochemical determination of methyl orange (MO). MO is recalcitrant and very difficult to degrade and can affect the humans as well as the environment. Therefore, we must determine the presence of MO. We have investigated the effect of scan rate, modifier and analyte concentration, and the pH variation on the anodic peak current (Ipa) of MO. The calculated active syrface area of bare carbon paste electrode (BCPE) and HEA-modified carbon paste electrode (HEA-MCPE) were found to be 0.041 cm2 and 0.137 cm2 respectively. We have obtained the maximum oxidation peak current for the 8 mg HEA-MCPE at a pH of 7.2 during the electrochemical oxidation of MO. The increased Ipa in basic medium is due to structural transformation of MO from quinoid form (in acidic medium) to azo structure (in basic medium). We have also calculated the number of electrons and the protons involved in the electrochemical reaction. The calculated values of detection limit (DL) and quantification limit (QL) of 8 mg HEA-MCPE was found to be 0.114 × 10−8 M and 0.38 × 10−8 M respectively.

Development of CuO nanoparticles modified electrochemical sensor for detection of salbutamol

Abstract Metal oxide structures are being utilized in an increasing variety of applications. This study used cyclic and differential pulse voltammetry techniques to investigate the possible utilization of copper oxide (CuO) nanoparticles modified carbon paste electrode (CPE) for the redox reactions of salbutamol (SAL). The electrochemical performance of the SAL analyte in a complex matrix environment in Ventolin was evaluated in order to assess the appropriateness of the proposed sensor in a real sample environment. CuO nanoparticles were produced via a straightforward, cost-effective and efficient sol–gel method, and characterization studies of synthesized CuO nanoparticles were performed by scanning electron microscopy, x-ray Diffraction (XRD), and x-ray photoelectron spectroscopy. The synthesized CuO nanoparticles had a spherical shape and particle size was found to be 74 nm. The crystal size of the CuO particles was calculated to be 21.79 nm using the Debye–Scherrer equation. Under optimal conditions, differential pulse voltammetry demonstrated a linear response in the 50 nM to 100 μM range, with a salbutamol detection limit of 50 nM (S/N = 3). The SAL concentration (R 2 = 0.9971) was found to have a good correlation coefficient. The reproducibility of the biosensor was investigated and evaluated with a relative standard deviation of 3% (n = 8). The storage stability of CuO modified CPE for two weeks was evaluated based on the response of DP current measured at intervals every two days. According to the measurement results, the modified electrode exhibited good stability and reproducibility while maintaining 80% of its stability. It is also a rapid and dependable sensor candidate with a measurement time of approximately 20 s. The developed electrode has been utilized successfully to determine doping material with improved performance.

Fabrication of Carbon Paste Sensor Activated with Electropolymerized DL‐Phenylalanine for the analysis of Levofloxacin

AbstractVoltammetric analysis of Levofloxacin (LF) using an electrochemically polymerized composite of DL‐phenylalanine (DLP) alongside a bare carbon paste electrode. The constructed electrodes are polymerized DL‐phenylalanine modified carbon paste electrodes P(DLP/MCPE) and bare carbon paste electrodes (BCPE). Cyclic voltammetry (CV), differential pulse voltammetry (DPV), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and other electrochemical techniques used for characterization of P(DLP/MCPE) and BCPE in 0.2 M phosphate buffer solution (PBS) with pH 4.5 were conformed using the P(DLP/MCPE), and it shows the highest current responses compared to the BCPE. This research work examines the effect of pH in PBS, scan rate, and LF concentration on the surface of P(DLP/MCPE). The outcome result shows that the oxidation reaction of LF pH is an adsorption‐controlled path. The detection limit of LF ranges from 0.2 μM to 7.0 μM, and the lower limits of detection (LOD) is 0.613x10−7 M and the lower limits of quantification (LOQ) is 2.051X10−7 M. The electrochemical P(DLP/MCPE) shows good repeatability, reproducibility, and stability. Finally, by analyzing LF in a pharmacological sample, the real time application of the sensor was assessed, and significant recoveries were observed.

Electrochemical behavior and determination of pyridoxine at chemically modified carbon paste electrode by electropolymerization

Electrochemical behavior and determination of pyridoxine at chemically modified carbon paste electrode by electropolymerization

Novel electrochemical sensing platform for accurate detection of benzylpenicillin based on a graphene oxide-manganese ferrite modified carbon paste electrode

Antibiotic overuse and environmental disregard result in water supply contamination, caused antibiotic resistance. Given the global health concern, developing a sensitive, simple, and low-cost antibiotic sensor is critical. In this study, graphene oxide was incorporated with MnFe2O4 to modify the carbon paste electrode (CPE) as a new electrochemical platform for detecting benzylpenicillin, the widely used antibiotic. A comparative chemical and structural characterization of the synthesized MnFe2O4 nanoparticles (NPs) and GO/MnFe2O4 nanocomposites (NCs) verified that the successful integration of spherical particles of MnFe2O4 NPs onto GO nanosheets produces a rough surface. Furthermore, the structure and electrochemical characterization of the developed GO/MnFe2O4/CPE were conducted via field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), cyclic voltammetry (CV), and impedance spectroscopy (EIS) techniques. The proposed electrode presented enhanced active surface area and electrocatalytic performance due to the superior features of the used modifiers, which work synergistically. The GO/MnFe2O4/CPE demonstrated a high-performance benzylpenicillin sensing platform, giving a detection limit of 145 nM and sensitivity of 15.16 μAμM-1cm−1 as measured by differential pulse voltammetry (DPV) within two dynamic ranges of 1–100 μM and 100–1000 μM. The created sensor was applied as a practical apparatus for the electrochemical determination of benzylpenicillin in water samples.

Challenging electroanalytical method for the determination of mirabegron in biological samples and pharmaceutical formulations

A simple, economic, sensitive, and time-saving differential pulse voltammetric (DPV) procedure using nanostructured zinc oxide modified carbon paste electrode (nano ZnO-CPE) in conjunction with an anionic surfactant sodium dodecyl sulfate (SDS) was developed for ultra- sensitive detection of mirabegron (MIR), the most prescribed pharmaceutical drug in treatment of overactive bladder (OAB). The use of nanostructured zinc oxide CPE modifier increased the electrode active surface area as well as improved the process of electron transfer, also it was found that at optimal conditions MIR electrochemical process was both irreversible and diffusion-regulated. The morphological characterization of the fabricated electrode was performed using field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX). MIR voltammetric behavior was investigated using Nano ZnO-CPE in different content and electrode compositions. Therefore, ultra-sensitive results were attained with a linearity range of (0.55 to 100.20 ng ml−1) and a low limit of detection (LOD) of 0.51 ng ml−1 and limit of quantification (LOQ) of 1.54 ng ml−1 in a 0.04 M Britton-Robinson (BR) buffer at an adjusted pH of 6.0 with scan rate 100 mV s−1. Furthermore, the proposed approach was successful in measuring MIR with acceptable percentage recoveries (99.81–100.11 %) in pharmaceutical dosage form and varying concentration ranges in biological samples (99.74–100.35 %). The proposed method has been validated using ICH criteria and proven to be accurate and repeatable.

Rapid and inexpensive method for bisphenol a detection in water samples based on alkaline activated fly ash modified carbon paste electrode

Rapid and inexpensive method for bisphenol a detection in water samples based on alkaline activated fly ash modified carbon paste electrode