Differential Pulse Voltammetry Method Research Articles

A Sensitive Enzymatic Electrochemical Biosensor for Cholesterol Based on Cobalt Ferrite@Molybdenum Disulfide/Gold Nanoparticles.

Cholesterol is essential in biological systems, and the level of cholesterol in the body of a person acts as a diagnostic marker for a variety of diseases. So, in this work, we fabricated an enzymatic electrochemical biosensor for cholesterol using cobalt ferrite@molybdenum disulfide/gold nanoparticles (CoFe2O4@MoS2/Au). The synthesized composite was used for the determination of cholesterol by voltametric methods. The electroactive material CoFe2O4@MoS2/Au was successfully verified from the physiochemical studies such as XRD, Raman, FT-IR, and XPS spectroscopy along with morphological FESEM and HRTEM characterization. CoFe2O4@MoS2/Au showed outstanding dispersion in the aqueous phase, a large effective area, good biological compatibility, and superior electronic conductivity. The microflower-like CoFe2O4@MoS2/Au was confirmed by scanning electron microscopy. The image of transmission electron microscopy showed decoration of gold nanoparticles on CoFe2O4@MoS2 surfaces. Furthermore, a one-step dip-coating technique was used to build the biosensor used for cholesterol detection. In addition to acting as an enabling matrix to immobilize cholesterol oxidase (ChOx), CoFe2O4@MoS2/Au contributes to an increase in electrical conductivity. The differential pulse voltammetry method was used for the quantitative measurement of cholesterol. The calibration curve for cholesterol was linear in the concentration range of 5 to 100 μM, with a low limit of detection of 0.09 μM and sensitivity of 0.194 μA μM-1 cm-2. Furthermore, the biosensor demonstrates good practicability, as it was also employed for identifying cholesterol in real samples with acceptable selectivity and stability.

CeO2 nanoparticles modified screen-printed carbon electrode: Electrochemical sensing platform for sulfite determination in water samples

In the present work, the CeO2 nanoparticles (CeO2 NPs) were prepared by hydrothermal method and the crystal structure and morphology analysis were studied by using a series of characterizations. Then, the screen-printed carbon electrode (SPCE) modified with CeO2 NPs was employed to develop a simple and novel sensor for sulfite determination in water samples. The CeO2 NPs/SPCE showed significant current response for sulfite oxidation. The use of the developed sensor with differential pulse voltammetry (DPV) method provides a wide linear range for sulfite determination (0.08–870.0 µM) with a low limit of detection (LOD) (0.023 µM). Finally, the results determination of sulfite in water samples showed good recoveries between 96.7% and 102.7% with a relative standard deviation (RSD) less than 3.6%.

Electrochemical biosensor for sensitive detection of SARS-CoV-2 gene fragments using Bi2Se3 topological insulator

In this study, we have designed an electrochemical biosensor based on topological material Bi2Se3 for the sensitive detection of SARS-CoV-2 in the COVID-19 pandemic. Flake-shaped Bi2Se3 was obtained directly from high-quality single crystals using mechanical exfoliation, and the single-stranded DNA was immobilized onto it. Under optimal conditions, the peak current of the differential pulse voltammetry method exhibited a linear relationship with the logarithm of the concentration of target-complementary-stranded DNA, ranging from 1.0 × 10-15 to 1.0 × 10-11 M, with a detection limit of 3.46 × 10-16 M. The topological material Bi2Se3, with Dirac surface states, enhanced the signal-to-interference plus noise ratio of the electrochemical measurements, thereby improving the sensitivity of the sensor. Furthermore, the electrochemical sensor demonstrated excellent specificity in recognizing RNA. It can detect complementary RNA by amplifying and transcribing the initial DNA template, with an initial DNA template concentration ranging from 1.0 × 10-18 to 1.0 × 10-15 M. Furthermore, the sensor also effectively distinguished negative and positive results by detecting splitting-synthetic SARS-CoV-2 pseudovirus with a concentration of 1 copy/μL input. Our work underscores the immense potential of the electrochemical sensing platform based on the topological material Bi2Se3 in the detection of pathogens during the rapid spread of acute infectious diseases.

A TALE OF CAPTOPRIL DETECTION BASED ON AN ELECTROCHEMICAL MIP SENSOR

Objective: In this study, it was aimed to develop a voltammetric method using sensors prepared with the molecular imprinting technique for the detection of Captopril, an antihypertensive drug. Material and Method: With the molecular imprinting method, molecularly imprinted polymers were formed on the surfaces of glassy carbon electrodes. The analysis of Captopril was carried out using the differential pulse voltammetry method, and the performance of the sensor was examined. Result and Discussion: A linear analysis was performed up to 50 pM Captopril with a limit of detection value of 2.62 pM. Selectivity studies have shown that Captopril has a higher electrochemical response than other interfering substances, such as paracetamol, ascorbic acid, and L-proline.

Uricase conjugated nanostructured NiFe2O4/rGO modified flexible screen-printed carbon electrode based interface for long-range electrochemical determination of uric acid

Uric acid (UA) is a biomarker linked with gout and kidney stones that is harmful to the human body. Thus, this study explores the detection of UA using the differential pulse voltammetry (DPV) method. Initially synthesizing a highly active Nickel ferrite/reduced graphene oxide (NiFe2O4/rGO) nanocomposite ferrite material by simple surfactant-free low-temperature hydrothermal approach. The as-synthesized material was studied using various spectroscopic and microscopic techniques. The bioelectrode was fabricated on a screen-printed carbon electrode (SPCE), and the as-prepared Uricase/NiFe2O4/rGO/SPCE demonstrated improved electrochemical oxidation peak current (Ipa). While its electrochemical biosensing performance towards various UA concentrations shows a wide linear range from 5 to 900 μM, with a lower limit of detection (21·9 μM), high sensitivity (1·05×10−4 mA/μM cm2), good selectivity (RSD < 5·7 %), excellent stability, and repeatability. In addition, the fabricated bioelectrode was also explored to quantify the amount of UA in bovine serum albumin (BSA) real spiked samples. Hence, the proposed biosensor has potential applications in point-of-care-treatment of numerous disorders related to UA metabolism.

New nanosensor fabricated on single nanopore electrode filled with prussian blue and graphene quantum dots coated by polypyrrole for hydrogen peroxide sensing

Hydrogen peroxide (H2O2) is a common oxidant that plays an important role in many biological processes and is also an important medium analysis in various fields. In this work, a new electrochemical nanosensor capable of detecting and quantifying hydrogen peroxide was introduced. This nanosensor was fabricated by electrodepositing prussian blue (PB)/graphene quantum dots (GQDs)/polypyrrole (PPy) on single nanopore electrode etched from single gold nanoelectrode. This prepapred nanosensor exhibits good electrochemical response to hydrogen peroxide with high sensitivity and stability, with a linear response in the 2.0 and 80 μM by using amperometric method and differential pulse voltammetry (DPV) method. The limit of detections are 0.33 μM (S/N = 3) for amperometric method and 0.67 μM (S/N = 3) for differential pulse voltammetry (DPV) method, respectively. This nanosensor can be used for the determination of hydrogen peroxide in human urine, and can serve as a new electrochemical platform to monitor H2O2 release from single living cells due to its small overal dimension and high sensitivity.

Layered Yttrium Oxide Reinforced Graphene Oxide Electrode Surface for Voltammetric Determination of Paracetamol

In this study, graphene oxide (GO) was synthesized by the Hummers method starting from graphite. Also, the sol-gel method synthesized yttrium oxide (YO) and was characterized by FTIR, XRD, SEM, and TEM techniques. The sensor performance of the modified electrode against the paracetamol analyte was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). As a result of the optimized voltammetric methods calculated the linear working range was 0.25-10.0 µM and the LOD value was 19.0 nM. With the DPV method, advanced analytical parameters such as stability, reproducibility, and selectivity were studied. Moreover, the performance of the new sensor to detect paracetamol in tablet real samples was examined.

Application of a Carbon Fiber Microelectrode as a Sensor for Apocynin Electroanalysis.

In this study, a carbon fiber microelectrode (CF) was applied for the investigation of the electrochemical behavior of the natural antioxidant, apocynin (APO). Given the limited solubility of APO in water, a mixture of anhydrous acetic acid (AcH) with 20%, v/v acetonitrile (AN) and 0.1 mol L-1 sodium acetate (AcNa) was used. The electrochemical properties of APO were examined through linear sweep voltammetry (LSV), differential pulse voltammetry (DPV), and cyclic voltammetry (CV). The anodic oxidation of APO, which is the basis of the method used, proved to be diffusion-controlled and proceeded with a two-electron and one proton exchange. Both radicals and radical cations, arising from the first and second step of electrode reactions, respectively, underwent subsequent chemical transformations to yield more stable final products (EqCiEiCi mechanism). Using optimized DPV conditions, the anodic peak current of APO at a potential of 0.925 V vs. Ag/AgCl showed a good linear response within the concentration range of 2.7 × 10-6-2.6 × 10-4 mol L-1. The detection and quantification limits were determined as 8.9 × 10-7 and 2.7 × 10-6 mol L-1, respectively. The developed DPV method enabled the successful determination of APO in herbal extracts and in dietary supplements. It should be noted that this is the first method to be used for voltammetric determination of APO.

An electrochemical tool for food additive: A nanoengineered sustainable approach on the preparation of t-LaVO4 rods decorated on g-carbon nitride nanocomposite for determination of theobromine

The dimethylxanthine alkaloid of theobromine (TB) naturally occurs in plants and their products. Derivatives of methylxanthine can potentially induce detrimental impacts on human health if ingested in excessive quantities or by individuals who are particularly susceptible to their effects. Therefore, a differential pulse voltammetry (DPV) method utilizing an electrode modified with a nanocomposite was proposed as an analytical approach for determining TB. Herein, the rare earth metal vanadate (REVO4) has recently played a key role in its use as an electrocatalyst in electrochemical sensors. REVO4's electronic characteristics enable electrochemical, optical, or impedance-based signal transduction and sensitive analyte detection. Due to these characteristics, REVO4 boosts sensing target analyte signals, enhancing sensor system sensitivity. In this paper, we constructed a sensor with nanostructured g-C3N4 entrapped LaVO4 nanomaterial successfully combined to make a nanocomposite to detect food analyte. Various voltammetric and spectroscopic techniques characterized the successfully prepared material LaVO4@g-C3N4 and its electrochemical behaviors. The electrochemical detection of TB, differential pulse voltammetric response was obtained in the wide linear range of 0.001–365 μM, the limit of detection (LOD) is 8 nM and the sensitivity of 4.03 μA μM−1 cm−2. The sensing platform of the electrochemical sensor successfully detected the extract of food samples such as water and chocolate milk samples and exhibited good recovery values of ±98.6–99.0%. The constructed sensor provides a robust means for monitoring alkaloids in complex matrices and a promising opportunity to develop sensitive and selective electrode materials with good reusability.

Purpald-functionalized biosensor for simultaneous electrochemical detection of ascorbic acid, uric acid, L-cysteine and lipoic acid

The polymer purpald (4-amino-3-hydrazino-5-mercapto-1,2,4-triazole) film on glassy carbon electrode (p-Purpald@GCE) was fabricated using purpald monomer by electropolymerization method, and the modified electrode was applied as a probe for the simultaneous sensing of ascorbic acid (AA), uric acid (UA), L-cysteine (L-Cys) and lipoic acid (LA). The modified p-Purpald@GCE was well characterized by Scanning electrode microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Cyclic Voltammetry (CV), Electrochemical impedance spectroscopy (EIS) and Differential Pulse Voltammetry (DPV) techniques. CV, EIS results were confirmed the good electrocatayst nature of p-Purpald@GCE. Independent and simultaneous detection of AA, UA, L-Cys, and LA ware performed by DPV method. For Independent detection, based on the oxidation current changes, we have calculated the limit of detection (LOD) of 392, 137, 341 and 200 nM (LOD) = 3S/m) for AA, UA, L-Cys and LA, respectively. The simultaneous detection of AA, UA, L-Cys, and LA executed and LOD found to be 364, 132, 275 and 192 nM, respectively. The modified electrode shows the high selectivity towards AA, UA, L-Cys and LA even in the presence of high concentration of other interferences. The developed sensor technique will be useful for the sensitive and simultaneous detection of AA, UA, L-Cys, and LA in food and clinical samples.

Carbon Nanotube Modified Glassy Carbon Electrodes for on‐line and off‐line in vitro Therapeutic Equivalence Assessment of Paracetamol Tablets

AbstractIn vitro bioequivalence assessment of paracetamol tablets was carried out by differential pulse voltammetry (DPV) and amperometry using a multiwalled carbon nanotube modified glassy carbon electrode (GCE/MWCNT). For the DPV developed method, samples were collected from the USP paddle apparatus, while amperometric measurements were carried out in situ. The DPV method was validated in three supporting electrolytes (per in vitro bioequivalence guidelines) by measuring the recovery from standard solutions and paracetamol tablet solutions, while precision was evaluated through the RSD (n=6). In HCl pH 1.2 solution the LOD and LOQ were 48 nM and 160 nM, respectively and the linear range was between 0.18–2.2 μM. In acetate buffer pH 4.5 the LOD and LOQ were 15 nM and 51 nM, respectively and the linear range was between 88 nM–880 nM. And in phosphate buffer pH 6.8 the LOD and LOQ were 4.6 nM and 15 nM, respectively and the linear range was between 88 nM–880 nM. Recovery values were between 95 and 105 % and precision values were less than 5 %. Results showed that both methods were effectively applied for the analysis of samples.

Voltammetric determination of genotoxic 4‐nitroindane at a mercury meniscus modified silver solid amalgam electrode

AbstractA silver solid amalgam electrode modified with mercury meniscus (m‐AgSAE) was used as a non‐toxic replacement of mercury electrodes in the voltammetric determination of genotoxic environmental pollutant 4‐nitroindane (4‐NI). The m‐AgSAE was used to characterize of the overall electrode process during the 4‐NI conversion using cyclic voltammetry (CV), and it was shown that the electrochemical reduction of 4‐NI is an irreversible process controlled by both diffusion and adsorption. Techniques of direct current voltammetry (DCV) and differential pulse voltammetry (DPV) at the m‐AgSAE were optimized for the development of a method for the sensitive determination of 4‐NI. The application of the more convenient DPV method was proven on authentic drinking and river water samples. Limits of quantification (LQs) obtained under the following optimal conditions were 0.1 μmol L−1 for DCV at the m‐AgSAE (Britton‐Robinson (BR) buffer pH 5.0–methanol (1 : 1); regeneration potentials E1,reg=−200 mV, E2,reg=−1100 mV) and 0.1 μmol L−1 for DPV at the m‐AgSAE (BR buffer pH 9.0–methanol (1 : 1); regeneration potentials E1,reg=−300 mV, E2,reg=−1300 mV). An attempt to decrease the LQ of the 4‐NI determination by differential pulse adsorptive stripping voltammetry at the m‐AgSAE was not successful. The LQs for DPV at the m‐AgSAE in authentic samples of drinking and river water were 1.0 μmol L−1 and 2.0 μmol L−1 (BR buffer pH 9.0–drinking or river water (1 : 9); regeneration potentials E1,reg=−300 mV, E2,reg=−1300 mV), respectively.

Novel MoS2-decorated Cu2O hybrid nanoparticles for enhanced non-enzymatic electrochemical cholesterol detection

Precise identification of cholesterol levels is crucial for the early diagnosis of cardiovascular risk factors. This paper presents a novel approach for cholesterol detection that circumvents the reliance on enzymatic processes. Leveraging the unique properties of advanced materials and electrochemical principles, our non-enzymatic approach demonstrates enhanced sensitivity, specificity, and limit of detection in cholesterol analysis. A non-enzymatic electrochemical biosensor for Cholesterol, employing a nanohybrid comprising Cu2O nanoparticles decorated with MoS2, is presented. The cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometry techniques were employed to investigate the electrochemical behaviour of the glassy carbon electrode modified with the Cu2O/MoS2 nanohybrid. The modified electrode exhibited an excellent sensitivity of 111.74 μA μM−1 cm−2 through the CV method and showcased a low detection limit of 2.18 μM and an expansive linear range spanning 0.1–180 μM when employing the DPV method. The electrode also showed good selectivity to various interfering components in 0.1 M NaOH and a satisfied stability of about 15 days at room temperature. The study demonstrates the potential for broader applications in clinical diagnostics and monitoring cardiovascular health, paving the way for a paradigm shift in cholesterol detection methodologies and offering a more efficient and cost-effective alternative to traditional enzymatic assays.

Voltammetric performance of nanofiber structured over-oxidized poly(3,4-ethylenedioxythiophene) modified pencil graphite electrodes for dobutamine sensing

A modified electrode was developed for the electrochemical sensing of dobutamine (DBT), one of the catecholamines. For this modification process, pencil graphite electrodes (PGE) were modified with over-oxidized nanofiber structured poly (3,4-ethylenedioxythiophene) (PGE/OPEDOTNF) by electropolymerization. The electrochemical performance of PGE/OPEDOTNF was evaluated by cyclic and differential pulse voltammetry. In addition, the performances of non-nanofiber PEDOT-modified PGE electrodes were also examined for comparison. The characterization of the modified electrodes was carried out by scanning electron microscopy and electrochemical methods. The signal of the modified electrodes was observed in a linear range of 0.1-2.0 µM against DBT using the differential pulse voltammetry method. The limit of detection and quantification are calculated as 0.026 µM and 0.086 µM, respectively. The effect of the interfering species was examined. It has been shown that DBT can be detected sensitively and selectively using pencil graphite electrodes modified with nanofiber-structured poly(3,4-ethylenedioxythiophene). The repeatability of PGE/OPEDOTNF electrodes was found to be 5.2%. PGE/OPEDOTNF electrodes remained stable for 15 days without losing their electrochemical activity.

Hydroxyapatite-Gold Modified Screen-Printed Carbon Electrode for Selective SARS-CoV-2 Antibody Immunosensor.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or coronavirus disease 2019 (COVID-19), is still spreading worldwide; therefore, the need for rapid and accurate detection methods remains relevant to maintain the spread of this infectious disease. Electrochemical immunosensors are an alternative method for the rapid detection of the SARS-CoV-2 virus. Herein, we report the development of a screen-printed carbon electrode immunosensor using a hydroxyapatite-gold nanocomposite (SPCE/HA-Au) directly spray-coated with the immobilization receptor binding domain (RBD) Spike to increase the conductivity and surface electrode area. The HA-Au composite synthesis was optimized using the Box-Behnken method, and the resulting composite was characterized by UV-vis spectrophotometry, TEM-EDX, and XRD analysis. The specific interaction of RBD Spike with immunoglobulin G (IgG) antibodies was evaluated by differential pulse voltammetry and electrochemical impedance spectroscopy methods in a [Fe(CN)6]4-/3- solution redox system. The IgG was detected with a detection limit of 0.0561 pg mL-1, and the immunosensor had selectivity and stability of 103-122% and was stable until week 7 with the influence of storage conditions. Also, the immunosensor was tested using real samples from human serum, where the results were confirmed using the chemiluminescent microparticle immunoassay (CMIA) method and showed satisfactory results. Therefore, the developed electrochemical immunosensor can rapidly and accurately detect SARS-CoV-2 antibodies.

Voltammetric approach to measuring free acid in anhydride and ester based on benzoquinone electrochemical reduction

AbstractFree acids commonly exist in anhydride and esters because they are unstable and tend to break down into free acids, which affect the quality of subsequent products in industrial production. Phthalic anhydride and ethyl acetate undergo hydrolysis reactions to form phthalic acid and acetic acid. A differential pulse voltammetry method for the determination of phthalic acid and acetic acid was developed with a bare glassy carbon electrode. Phthalic acid and acetic acid caused a new cathodic peak at more positive potential during the reduction of 1,4‐benzoquinone in acetonitrile or aqueous solution. The new peaks are attributed to the drastic increase in pH at the electrode surface caused by the consumption of protons in the benzoquinone reduction reaction. The peak current of the new cathodic peak was dependent on the concentration of phthalic acid and acetic acid but independent of BQ, phthalic anhydride, and ethyl acetate. This method does not cause hydrolysis of anhydride and ester because no external base is introduced. Furthermore, the method is sensitive, rapid, and does not require pretreatment.

The development of electrochemical DNA biosensor based on woolen ball-shaped La3+/TiO2 nanostructure coating: Nanomolar detection of Vinorelbine

Although Vinorelbine (VOB) is a powerful anticancer medication, it inevitably has a number of adverse effects. Therefore, identifying this medication in biological samples is crucial for assessing both its effectiveness and negative effects. In this study, a new DNA biosensor was created to analyze VOB within biological samples. Moreover, the sensor has been created though the modification of a pencil graphite electrode (PEG) with polypyrrole (PP), a woolen ball-shaped La3+/TiO2 nanostructure (WB–S La3+/TiO2-NS) (enhancing the conductivity of electricity), along with ds-DNA (calf thymus) (ds-DNA/PP/WB-S La3+/TiO2-NS/PGE). Alterations in electrode signal has been then utilized to determine whether VOB is present. Under optimized condition, the differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques were adopted for electrochemical sensing of VOB. With a 0.37 nM detection limit, ds-DNA/PP/WB-S La3+/TiO2-NS/PGE demonstrated remarkable sensitivity for VOB at concentrations between 0.001 and 150.0 μM by DPV method. In addition, the calibration curve shows a linear range between 5.0 and 100.0 μM vanillin with a detection limit of about 0.76 μM by EIS method. Theoretical docking investigation was used to analyze the contacts among VOB and ds-DNA bases for future assessments, and the results supported the intercalation of VOB with guanine bases ds-DNA's intercalations. VOB was examined using the ds-DNA/PP/WB-S La3+/TiO2-NS/PGE method in actual samples.

A ferrocene-based hydrogel as flexible electrochemical biosensor for oxidative stress detection and antioxidation treatment

Real-time sensing of reactive oxygen species (ROS) and timely scavenging of excessive ROS in physiological environments are critically important in the diagnosis and prevention of ROS-related diseases. To solve the mismatch problem between conventional rigid ROS biosensors and biological tissues in terms of both modulus and composition, here, we present a flexible ferrocene-based hydrogel biosensor designed for oxidative stress detection and antioxidation treatment. The hydrogel was fabricated through a supramolecular assembly of ferrocene-grafted polyethylenimine (PEI-Fc), sodium alginate (SA), and polyvinyl alcohol (PVA). Multiple non-covalent interactions, including electrostatic interactions between PEI-Fc and SA, hydrophobic interactions and π–π stacking among ferrocene groups, and the PVA crystalline domain, synergistically improve the mechanical properties of the PVA/SA/PEI-Fc hydrogel. The flexible PVA/SA/PEI-Fc hydrogel biosensor exhibited a broad detection range for hydrogen peroxide (H2O2), from 0 to 120 μM, using the differential pulse voltammetry method. Furthermore, the hydrogel demonstrated effective ROS scavenging and oxygen generation performance, desirable biocompatibility, and satisfactory antibacterial activity, making it suitable for biological interfaces. In vitro studies revealed that the PVA/SA/PEI-Fc hydrogel could monitor H2O2 concentration in the proximity of inflammatory cells, and effectively scavenge ROS to protect cells from oxidative stress damage. This all-in-one multifunctional hydrogel, integrating both sensing and treatment functions, holds great promise for clinical applications in the diagnosis and management of ROS-related diseases.

An on-site and portable electrochemical sensing platform based on spinel zinc ferrite nanoparticles for the quality control of paracetamol in pharmaceutical samples.

In this study, crystalline spinel zinc ferrite nanoparticles (ZnFe2O4 NPs) were successfully prepared and proposed as a high-performance electrode material for the construction of an electrochemical sensing platform for the detection of paracetamol (PCM). By modifying a screen-printed carbon electrode (SPE) with ZnFe2O4 NPs, the electrochemical characteristics of the ZnFe2O4/SPE and the electrochemical oxidation of PCM were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and differential pulse voltammetry (DPV) methods. The calculated electrochemical kinetic parameters from these techniques including electrochemically active surface area (ECSA), peak-to-peak separation (ΔEp), charge transfer resistance (Rct), standard heterogeneous electron-transfer rate constants (k0), electron transfer coefficient (α), catalytic rate constant (kcat), adsorption capacity (Γ), and diffusion coefficient (D) proved that the as-synthesized ZnFe2O4 NPs have rapid electron/mass transfer characteristics, intrinsic electrocatalytic activity, and facilitate the adsorption-diffusion of PCM molecules towards the modified electrode surface. As expected, the ZnFe2O4/SPE offered excellent analytical performance towards sensing of PCM with a detection limit of 0.29 μM, a wide linear range of 0.5-400 μM, and high electrochemical sensitivity of 1.1 μA μM-1 cm-2. Moreover, the proposed ZnFe2O4-based electrochemical nanosensor also exhibited good repeatability, high anti-interference ability, and practical feasibility toward PCM sensing in a pharmaceutical tablet. Based on these observations, the designed electrochemical platform not only provides a high-performance nanosensor for the rapid and highly efficient detection of PCM but also opens a new avenue for routine quality control analysis of pharmaceutical formulations.

Facile synthesis of limeonia acidissima shell derived carbon-vanadium pentoxide nanocomposite for sensitive detection of carbofuran

Generating carbonaceous materials from agricultural waste is a sustainable and environmentally friendly method of producing activated carbon. In the current work, carbon is extracted using a tubular furnace from the shell of the wood apple (Limonia acidissima) V2O5 (C/VO) and synthesized carbon were combined to form a nanocomposite. The formation of nanocomposite is confirmed by X-ray diffraction (XRD) investigations, X-ray photoelectron spectroscopy (XPS), and other morphological characterizations. Modification of glassy carbon electrode (GCE) was done using synthesized materials (C@GCE, VO@GCE, and C/VO@GCE). The enzyme-free detection of carbofuran (CBF) in 0.1 M phosphate buffer was carried out using fabricated electrodes. Among the various electrode systems, C/VO@GCE demonstrated enhanced electrochemical performance for CBF detection using both cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. V/C@GCE demonstrated its capacity to identify CBF within a 0.05–750 μM range, with a limit of detection (LOD) of 0.06 μM. Using DPV, the effect of several pesticides on CBF detection in the presence of C/V@GCE was assessed, and good anti-interfering properties were discovered. When the DPV approach was used to detect CBF in potatoes, the recovery rate ranged from 98.0 to 99.0 %. According to a stability study, C/V@GCE has an 80.8 % retention capacity and can detect CBF for up to 24 days. The promise of the constructed electrode towards sensor applications is indicated by the large linear range, low LOD, selectivity, and stability of C/V@GCE.