Differential Pulse Voltammetry Analysis Research Articles

Highly efficient electrocatalysts of NiMoO4 doped CdO nanostructure interconnected with modified glassy carbon electrode for the detection of chloramphenicol

In this study, we developed an excellent electrocatalyst of NiMoO4 doped with CdO and then coated electrochemical detection of chloramphenicol (CAP) via a glassy carbon electrode (NiMoO4@CdO/GCE). In particular, this drug treats typhoid, fever, and salmonellosis infections. CAP detection and measurements have become progressively important in ensuring human safety. The NiMoO4@CdO nanocomposite was prepared using the one-step hydrothermal method and characterized for its structural and optical properties. The electrochemical determination of CAP was investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) techniques. We observed that the glassy carbon electrode modified with NiMoO4@CdO efficiently reduced the CAP at a very low potential. While CAP interacts with this system, metal oxide nanocomposites can combine with CAP reduction to produce phenylhydroxylamine. According to the DPV analysis, the bare electrode provides a linear response in the 10–100 µM range and a substantial reduction in CAP over a low detection limit of 0.083 µM when compared to (NiMoO4@CdO/GCE). Other co-existing molecules challenge the utility of this sensor. Additionally, this sensor exhibited high selectivity, stability, and reproducibility. Further, we evaluated the sensor for real-sample analysis, and the results were satisfactory.

Bioreceptors’ immobilization by hydrogen bonding interactions and differential pulse voltammetry for completely label-free electrochemical biosensors

Label-free electrochemical biosensors show great potential for the development of point-of-care devices (POCDs) for environmental and clinical applications. These sensors operate with shorter analysis times and are more economic than the labelled ones. Here, four completely label-free biosensors without electron transfer mediators were developed for hepatitis B virus (HBV) detection. The approach consisted in (i) the modification of gold surfaces with cysteamine (CT) or cysteine (CS) linkers, (ii) the subsequent antibody (Ab) immobilization, either directly by hydrogen bonding (HB) interactions or by covalent bonds (CB) using additional reagents, and (iii) measuring the biosensor response by electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The electrode surfaces at each stage of the modification process were characterised by X-ray photo-electron spectroscopy (XPS) and atomic force microscopy (AFM). The combination of Ab immobilization by HB with the DPV analysis displayed improved repeatability, lower interference to serum matrix and similar limits of detection and quantification than the traditional biosensors that immobilize the Ab via CB and use EIS as readout technique. The Ab immobilization by HB is shown as a simple, efficient and low-cost alternative to CB ones, while DPV was faster and showed better performance than EIS. The CT-HB biosensor displayed the lowest limits of detection and quantification of 0.14 and 0.46 ng/mL, respectively, a 0.46–12.5 ng/mL linear analytical range, and 100% of recovery for 1/10 human serum media during HBV surface antigen detection by DPV. Even, it preserved the initial sensing capability after 7 days of its fabrication.Graphical abstract

Design of an electrochemical hydrogel nanocomposite immunosensor for the detection of hemoglobin in blood

A novel hybrid hydrogel nanocomposite immunosensor was developed for the electrochemical detection of hemoglobin in blood. The transducing element was based on carbon black (CB)-nanomodified screen-printed electrodes (SPEs) on which a poly(ethylene glycol)-diacrylate hydrogel (PEGDA) doped with gold nanoparticles (AuNPs) was photopolymerized in situ. The fabricated PEGDA-AuNPs/CB-SPEs were then functionalized with oriented anti-hemoglobin antibodies. The immunosensor was analyzed by Electrochemical Impedance Spectroscopy (EIS) and Differential Pulse Voltammetry (DPV) at different modification steps, while its morphology was evaluated by Scanning Electron Microscopy (SEM). The analytical performances of the resulting PEGDA-AuNPs/CB-SPE immunosensor were assessed by DPV analysis, demonstrating the ability of the proposed system to detect hemoglobin in both standard solution and serum samples with a limit of detection (LOD) of 0.005 mg/mL within a dynamic response in a concentration range from 0.005 to 0.1 mg/mL. Slight interference was observed in the presence of glucose and ascorbic acid at concentrations much higher than those physiologically present in the blood. Moreover, any matrix effect was evidenced in serum samples, with a good recovery value of 107 ± 4 % obtained for a hemoglobin concentration of 0.025 mg/mL.

Electrochemical detection of salicylic acid in fruit products with ternary ZnO/CuO/Y2O3 nanocomposites embedded PEDOT:PSS by differential pulse voltammetry

In this approach, a novel electrochemical sensor for the determination of salicylic acid (SA) in fruit juices was developed using a nanocomposite (NC) of ZnO/CuO/Y2O3 coated on a glassy carbon electrode (GCE). The ternary metal oxide NCs were synthesized via a facile hydrothermal method and thoroughly characterized using techniques such as X-ray photoelectron spectroscopy (XPS), X-Ray diffraction analysis (XRD), UV–Vis spectroscopy (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), and Energy-Dispersive X-Ray Spectroscopy (EDS). The NCs were then used to modify a flat-polished GCE surface, with a conducting polymer binder (PEDOT:PSS) used to facilitate the coating. Differential pulse voltammetry (DPV) was employed for the selective electrochemical detection of SA using this NC-modified GCE sensor. The DPV analysis exhibited a linear relationship between the peak current and SA concentration over a wide range of 1.5 ∼ 15.0 μM, indicating a large linear dynamic range. The sensor demonstrated excellent sensitivity, with a value of 5.79 μA μM−1 cm−2, and a low limit of detection of 0.18 ± 0.09 μM for SA. Additionally, the sensor’s performance was evaluated in terms of pH optimization, response time, stability, reproducibility, and repeatability. Importantly, the developed ZnO/CuO/Y2O3 NC-modified GCE sensor was successfully applied to the analysis of real fruit juice samples, showcasing its potential for practical applications in food analysis and quality control.

Integration of Samarium Vanadate/Halloysite Nanotubes: Electrochemical Determination of Furaltadone Using Flexible Electrode

In this study, a composite comprising a rare‐earth metal, samarium vanadate (SmVO4, SmV), anchored to halloysite nanotube (HNT) making SmV/HNT nanocomposite is synthesized for the sensitive electrochemical determination of furaltadone (FLD) through differential pulse voltammetry analysis based on the synergistic effect of SmV/HNT (the catalytic activity and chemical stability of SmV, which was further boosted by the improved surface area and conductance of HNT). Further, in the microscopic studies, it is revealed that SmV exhibits a tetragonal zircon‐type crystalline structure, with I41/amd (141) space group, whereas HNT comprises a multiphase kaolin composition as a gibbsite‐like octahedral sheet with multivalency, and the morphological irregularities of the individual constituents are rectified in the composite. The SmV/HNT composite is spray‐coated on polyethylene terephthalate sheet, which delivered a promising trace level limit of detection (0.009 μm) over a wide working range (0.05–194.4 μm) for FLD. Furthermore, real sample analysis is performed using human serum, and pharmaceutical tablet and the results reveal exceptional repeatability and sensitivity, indicating the real‐time application of SmV/HNT in the pharmaceutical domain.

Cerium vanadate/functionalized carbon nanofiber composite for the electrochemical detection of nitrite

This study presents a facial and quick electrochemical sensor platform that offers remarkable water and food safety applications. The present work represents a study of the synthesis and characterization for efficient cerium vanadate (CeVO4) with a functionalized carbon nanofiber (f-CNF) decorated electrode, which is a highly effective electrode modifier for sensitive nitrite detection. The CeVO4 nanoparticles were synthesized using the facial hydrothermal technique, and a composite (CeVO4@f-CNF) was prepared using the sonication method. Afterward, the produced materials were confirmed with spectroscopic and microscopic analysis. The electrochemical behavior of nitrite was studied through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The DPV analysis depicts an excellent linear range of 0.1˗1033 μM and a promising detection limit of 0.004 μM for the proposed electrode. The CeVO4@f-CNF electrode was applied to detect nitrite in water and meat samples. The proposed electrochemical sensor attributes the significant results towards the detection of nitrite.

Synthesis of Copper Molybdate and Its Electrochemical Sensing of Paracetamol.

Background In recent years, significant advancements have been made in various scientific sectors, particularly in healthcare and pharmaceutical research. This progress has been driven by the development of enhanced sensing materials and methodologies. Electrochemical sensing has become an important tool in detecting and analyzing drug molecules due to its high sensitivity, specificity, and rapid response times. Among various drugs, paracetamol, also known as acetaminophen, is widely used for its analgesic and antipyretic properties. Accurate detection of paracetamol is crucial due to its widespread use and potential for overdose, which can lead to severe liver damage.Copper molybdate (CuMoO4) is a transition metal oxide that has garnered attention for its excellent electrical conductivity and electrochemical stability. These properties make it a promising candidate for use in electrochemical sensors. The ability of CuMoO4 to act as a sensor material is enhanced by its unique structural and morphological characteristics, which can be tailored during synthesis. Aim This study aimed to synthesize CuMoO4 and investigate its electrochemical sensing capability for the detection of drug molecules, specifically paracetamol. Materials and method CuMoO4 was synthesized using a precipitation method that did not involve any surfactants. This approach was chosen to simplify the synthesis process and avoid potential contamination from surfactants. The morphology of the synthesized CuMoO4 nanoparticles was investigated using a field emission scanning electron microscope (FE-SEM). Energy-dispersive X-ray spectroscopy (EDX) confirmed the purity of the CuMoO4 nanomaterial. Structural analysis was performed using X-ray diffraction (XRD). To evaluate the electrochemical sensing capability of CuMoO4for paracetamol, Differential pulse voltammetry (DPV) was employed. DPV is a sensitive electrochemical technique that can detect changes in current response corresponding to the presence of analytes. Results The synthesized CuMoO4exhibited a rock-like structure, as revealed by FE-SEM imaging. This morphology is advantageous for electrochemical applications due to the increased surface area available for interaction with analytes. EDXconfirmed the purity of the CuMoO4nanomaterial, showing no significant impurities. XRD analysis indicated that the CuMoO4nanoparticles were crystalline in nature, which is beneficial for consistent and reproducible electrochemical behavior. The DPV analysis demonstrated that the CuMoO4sensor exhibited a linear increase in current response with increasing concentrations of paracetamol. This linear relationship indicates that CuMoO₄ is capable of detecting paracetamol effectively, with a strong and quantifiable signal response. Conclusion The CuMoO4nanomaterial was successfully synthesized using a simple precipitation method and was characterized by its rock-like morphology and crystalline structure. Electrochemical testing using DPV showed that CuMoO4has excellent sensing capabilities for detecting paracetamol, with a clear and linear current response. These findings suggest that CuMoO4is a promising electrochemical sensing material for drug detection, potentially offering a reliable and efficient method for monitoring paracetamol and possibly other pharmaceuticals in various settings.

A nanoDiamond/gold nanoparticle-based electrochemical immunosensor for the detection of HER 2 cancer biomarker

We report a highly sensitive electrochemical immunosensor based on a nanohybrid platform for the detection of the breast cancer biomarker human epidermal growth factor receptor 2 (HER 2). NanoDiamond (nanoD) and gold nanoparticles (AuNPs) immobilised by drop coating and electrodeposition methods, respectively, were employed to fabricate an immunosensor for HER 2 detections on a glassy carbon electrode (GCE). Voltammetry and electrochemical impedance spectroscopy (EIS) techniques were used to characterise each step of the modification process of the immunosensor. In addition, transmission electron microscopy (TEM), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) techniques were used to characterise the materials used to fabricate the modified electrode. Under optimal conditions of temperature, time, and pH (35 °C, 50 min, and pH 7.2), different concentrations were investigated within a wide range of 1 pg mL−1 to 50 ng mL−1 using differential pulse voltammetry (DPV). With a low detection limit of 0.29 pg mL−1 from the DPV analysis, the immunosensor showed very good sensitivity and had a high specificity for HER 2. Additionally, the immunosensor demonstrated good applicability in the analysis of HER 2 in human serum samples, demonstrating a potential for use in the early identification of breast cancer.

Fabrication of label-free immunoprobe for monkeypox A29 detection using one-step electrodeposited molybdenum oxide-graphene quantum rods

Monkeypox is a zoonotic viral infection caused by the monkeypox virus (MPXV), which belongs to the Poxviridae family of the Orthopoxvirus (OPXV) genus. Monkeypox is transmitted from animals to humans and humans to humans; therefore, the accurate and early detection of MPXV is crucial for reducing mortality. A novel graphene-based material, graphene quantum rods (GQRs) was synthesized and confirmed using high-resolution transmission electron microscopy (HR-TEM) and atomic force microscopy (AFM). In this study, molybdenum oxide was electrodeposited and one-pot electrodeposition of MoO3-GQRs composite on carbon fiber paper (CFP) enabled by an antibody (Ab A29)/MoO3-GQRs immunoprobe was developed for the early diagnosis of MPXV protein (A29P). Several studies were conducted to analyze the MoO3-GQRs composite, and the prepared Ab A29/MoO3-GQRs immunoprobe selectively bound to the A29P antigen that was measured using differential pulse voltammetry (DPV) analysis and impedance spectroscopy. The antigen–antibody interaction was analyzed using X-ray photoelectron spectroscopy. DPV analysis showed a wide linear range of detection from 0.5 nM to 1000 nM, a detection limit of 0.52 nM, and a sensitivity of 4.51 µA in PBS. The prepared immunoprobe was used to analyze A29P in serum samples without reducing electrode sensitivity. This system is promising for the clinical analysis of A29P antigen and offers several advantages, including cost-effectiveness, ease of use, accuracy, and high sensitivity.

Effective monitoring of environmental hazardous drug moxifloxacin hydrochloride using silver selenide on octadecyl amine modified reduced graphene oxide composite

The precise detection of antibiotics is very critical. Here, silver selenide (Ag2Se) nanorods are hydrothermally synthesized and ultrasonically treated with rGO surface modified with octadecylamine (rGO-ODA). The optical, structural, morphological, and functional analysis were performed which revealed the orthorhombic pattern of the P2221 E space group, the crystalline purity of Ag2Se, and the substantial composite formation. The morphological studies revealed nanorod like structure of the Ag2Se material and wrinkled sheets of rGO-ODA. A sensor that detects moxifloxacin hydrochloride (MOXH) antibiotic using the cyclic voltammetry (CV), differential pulse voltammetry (DPV) and UV-Vis absorbance was developed. For DPV analysis, a quite low value for detection limit 12.46 nM was exhibited with 0.199 μM – 425.16 μM linear range, and a sensitivity of 5.0439 μA M−1cm−2. For UV-Vis, the sensor demonstrated a very low limit of detection 17.42 nM over 0.12 μM – 7.7 μM working range. The use of this sensor was validated in real-time analysis with industrial waste water, fish, human blood, and urine samples. The results suggested an excellent rate of analyte recovery and enhanced efficiency for MOXH detection with a potential for commercialization in the future.

Polymeric nanocomposite electrode for enhanced electrochemical detection of α-lipoic acid: Application in neuroinflammation prevention and clinical analysis

Using poly (vanillin-co-chitosan)/functionalized MWCNTs/GCE (PV-CS/f-MWCNTs/GCE) as a polymeric nanocomposite modified electrode, the present investigation has been conducted on the electrochemical detection of α-lipoic acid (α-LA) to prevent the activation of microglia inflammation of the nervous system. The manufacture of modified polymeric nanocomposite electrodes was carried out using the established electropolymerization process. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analyses of structure revealed that the electropolymerization of poly (vanillin-co-chitosan) on the surface of the f-MWCNTs modified electrode was successful. Vanillin-co-chitosan electropolymerization on f-MWCNTs as electroactive sheets can enhance the signal for α-LA electrochemical sensors, according to research on the electrochemical characteristics utilizing cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methodologies. The PV-CS/f-MWCNTs/GCE demonstrated that it had a sensitivity of 0.04664 μA/μM, a detection limit of 0.012 μM, and an excellent response, linear range, and wide linear range to α-LA from 0 to 3000 μM. The results of the application of PV-CS/f-MWCNTs/GCE for determining the concentration of α-LA in a prepared real sample of human serum by DPV and human lipoic acid ELISA Kit analyses via standard addition method illustrated the substantial conformity between the findings of both assays. The results of the DPV analyses resulted in acceptable recovery values (97.60%–99.10%) and appropriate values of the Relative Standard Deviation (RSD) (3.58%–5.07%), which demonstrated the great applicability and accuracy of the results of PV-CS/f-MWCNTs/GCE for determining α-LA concentration in biological fluids and pharmaceutical specimens.

Ultra-sensitive electrochemical sensors for simultaneous determination of dopamine and serotonin based on titanium oxide-gold nanoparticles-poly Nile blue (in deep eutectic solvent)

Determining blood serum levels of dopamine (DA) and serotonin (SE), which are important neurotransmitters, is of great importance in diagnosing and treating many diseases. In this work, a new disposable sensor was developed for the simultaneous determination of DA and SE. First, titanium oxide nanoparticles (TiO2NP) were modified on the screen-printed carbon electrodes (SPCE) by physical adsorption. Then, AuNP was coated on SPCE/TiO2NP by cyclic voltammetry (CV). Finally, a deep eutectic solvent (DES) appropriate for green chemistry, ethylene glycol/choline chloride, was used to electro-polymerize Nile blue (NB) on SPCE/TiO2NP/AuNP. The materials of TiO2NP, AuNP, and PNBDES were characterized by FE-SEM-EDX, XRD, and FTIR. The effects of TiO2NP, AuNP, and PNBDES modification order on the electrode surface on the separation of differential pulse voltammetry (DPV) peaks of DA and SE were investigated. DPV analysis conditions (deposition time and potential) and pH effect were examined. Analytical parameters of the prepared sensor were determined for both individual and simultaneous determination of DA and SE. The detection limits (3 σ/m) for simultaneous detection are 1.39 nM and 2.47 nM for DA and SE, respectively. The sensor's repeatability, reproducibility, and reusability were examined for the simultaneous determination of DA and SE. Application stability of the developed sensor was determined as 20 days and storage stability as 4 weeks. The selectivity of the DA and SE sensor in the presence of ascorbic acid, uric acid, glucose, and citric acid was investigated, and it was observed that the selectivity of the sensor was satisfactory. The disposable sensor simultaneously determined DA and SE in blood serum samples, and high recoveries were acquired. A new disposable sensor with great repeatability and reproducibility was created for the quick, practical, selective, and simultaneous analysis of DA and SE at low concentrations.

A molecularly imprinted screen-printed carbon electrode for electrochemical epinephrine, lactate, and cortisol metabolites detection in human sweat

This study presents a novel approach to the detection of epinephrine, lactate, and cortisol biomarkers in human sweat using molecularly-imprinted polymers (MIP) embedded screen printed carbon electrode (SPCE) sensors. The epinephrine and lactate MIP SPCE sensors were fabricated by epinephrine or lactate-imprinted polyaniline co-polymerized with 3-aminophenylboronic acid and gold nanoparticles (PANI-co-PBA/AuNP) selective membrane on a commercial SPCE. The cortisol sensor was comprised of a cortisol-imprinted poly(glycidyl methacryate-co-ethylene glycol dimethacrylate) (poly (GMA-co-EGDMA)@AuNP selective membrane deposited on a SPCE. Both cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used as modes of analysis for the MIP SPCE sensors. All sensors exhibited a rapid (∼1 min) and selective response to the epinephrine, lactate, and cortisol target analytes, with excellent precision between scans for both CV and DPV analysis modes. For CV, the LOD for epinephrine, lactate, and cortisol was 8.2 nM, 13 mM, and 0.042 μM, respectively. The LOD for DPV were 0.60 nM, 2.2 mM, and 0.025 μM for epinephrine, lactate, and cortisol, respectively. The MIP SPCE sensor platforms were further validated through the successful quantification of epinephrine, lactate, and cortisol in human sweat.

Carbon nanotubes modified reticulated vitreous carbon materials enhancing extracellular electron transfer of Shewanella loihica PV-4

Increasing current output of bioelectrochemical devices is crucial for their real-world application. Electrodes modified with conductive nanoparticles increase the contact area between anodic microorganisms and solid electron acceptors, thus resulting in higher cells concentration and current output. Electron transfer mechanisms in Shewanella loihica PV-4 viable biofilms formed at carbon nanotubes (CNTs)-coated RVC electrode is investigated in potentiostat-controlled electrochemical cells set at oxidative potentials. Chronoamperometry showed a stable biofilm growth with final current output above 150 µA·cm−2 within two weeks, which was 3 times higher than unmodified RVC systems. The current output showed biphasic growth, which could be attributed to outer layer and inner layer biofilm growth, respectively, where aerobic and anaerobic growth occurred, respectively. Cyclic voltammetry and differential pulse voltammetry analysis indicated a contribution from both direct electron transfer (DET) and mediated electron transfer (MET) mechanisms. In the early stage, DET was dominant and contributed to biofilm formation. In the late stage, the contribution from MET to the overall extracellular electron transfer (EET) eventually became dominant. The mediators could be confined into the biofilm matrix and produce continuous current output. Scanning electron microscopy (SEM) showed that the bacteria distributed uniformly on the electrode surface, which enhanced the EET rate. The high surface of the RVC-CNTs electrode was accessible to biofilms in short-term batch experiments, and RVC-CNTs could be a potential anodic material for bioelectrochemical devices.

ZnO nanoparticles-copper metal-organic framework composite on 3D porous nickel foam: a novel electrochemical sensing platform to detect serotonin in blood serum

Herein, we report a simple non-enzymatic electrochemical sensor for the detection of serotonin (5-HT) in blood serum using ZnO oxide nanoparticles-copper metal-organic framework (MOF) composite on 3D porous nickel foam, namely, ZnO-Cu MOF/NF. The x-ray diffraction analysis reveals the crystalline nature of synthesized Cu MOF and Wurtzite structure of ZnO nanoparticles, whereas SEM characterization confirms the high surface area of the composite nanostructures. Differential pulse voltammetry analysis under optimal conditions yields a wide linear detection range of 1 ng ml−1 to 1 mg ml−1 to 5-HT concentrations and a LOD (signal to noise ratio = 3.3) of 0.49 ng ml−1, which is well below the lowest physiological concentration of 5-HT. The sensitivity of the fabricated sensor is found to be 0.0606 mA ng−1 ml−1.cm2, and it exhibited remarkable selectivity towards serotonin in the presence of various interferants, including dopamine and AA, which coexist in the real biological matrix. Further, successful determination of 5-HT is achieved in the simulated blood serum sample with a good recovery percentage from ∼102.5% to ∼99.25%. The synergistic combination of the excellent electrocatalytic properties and surface area of the constituent nanomaterials proves the overall efficacy of this novel platform and shows immense potential to be used in developing versatile electrochemical sensors.

Designing hybrid nanocubes-like cobalt stannate with appliance of MWCNT's nano composite for electrochemical detection of dopamine in bio-clinical samples

In this work, Co2SnO4 having nanocubes like structure synthesized via simple co-precipitation method and the nano-composite was prepared with appliance of multi-walled carbon nanotubes (MWCNT's) and employed for the determination of neuro-transmittance of dopamine (DA) in biological sample. The Co2SnO4 nanocubes and Co2SnO4@MWCNTs are characterized through distinct spectroscopic and microscopic methods, such as Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction spectroscopy (XRD), Raman spectroscopy, Filed emission scanning electron microscopy (FE-SEM), and electron spectroscopy for chemical analysis (ESCA) and as well as electrocatalytic activity was examined by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry techniques. Under optimal circumstances, the nano composite exhibited better activity over bare GCE. Moreover, Glassy carbon electrode (GCE) modified with Co2SnO4@MWCNTs was high sensitive and selective towards the determination of DA in presence of common interfering biomolecules. The electro analytical parameters via wide linear range (50–350 nM), low detection limit of 10.3 nM, sensitivity 0.043 nM mAcm−2 obtained by DPV analysis. The reliability of the Co2SnO4@MWCNTs/GCE electrode confirmed by real sample analysis of human urine sample and dopamine hydrochloride injection shows favor recovery percentage.

Two dimensional architectures of graphitic carbon nitride with the substitution of heteroatoms for bifunctional electrochemical detection of nilutamide

The exploration of graphitic carbon nitride (g-C3N4), a two-dimensional (2D) metal-free polymer semiconducting material, is largely discussed due to its large specific surface area, high electrical conductivity, thermal stability, and adaptable electronic structure. The adaption of sulfur (S) and phosphorous (P) atoms into the layers of g-C3N4 increases the electrochemical performance of detecting nilutamide (NT). The aggregation severity can be decreased by integrating S/P into g-C3N4, thereby improving surface area and electrical conductance. The g-C3N4, S/gC3N4, P/g-C3N4, and S/P/g-C3N4 were studied with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Fourier transform infrared (FTIR), Ultraviolet visible spectroscopy (UV), Thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET). The well-assigned S/P/g-C3N4 exhibited a good crystalline structure with more active sites for improved electron transfer toward NT detection. Both differential pulse voltammetry (DPV) and amperometry (IT) was studied for NT detection. The electrochemical studies were done with a linear range of 0.019–1.17 μM to 5.36–1891.98 μM in DPV and 0.01 μM–158.3 μM in IT technique. The attained limit of detection in DPV analysis was 3.2 nM and with IT analysis 2.4 nM. The nanocomposite S/P/g-C3N4 shows good selectivity towards NT. The fabricated electrode showed excellent repeatability, reproducibility, and stability, with a significant recovery range in real sample analysis.

Electrochemical detection of nickel(II) and zinc(II) ions by a dicarboxyl-Calix[4]arene-based sensor (Calix/MPA/Au) through differential pulse voltammetry analysis

Abstract Herein, we report a facile approach for constructing a calixarene-based electrochemical heavy metal sensor (Calix/MPA/Au) via a one-pot reaction for the detection of Ni(II) and Zn(II) ions. The surface elemental properties and analytical performance of the Calix/MPA/Au sensor were characterized by X-ray photoelectron spectroscopy (XPS) and differential pulse voltammetry (DPV). Under optimum conditions, the sensor exhibited detection limits of 1.5 and 0.34 mg/L at linear ranges of 2.85–6.65 and 0.13–1.68 mg/L for the Zn(II) and Ni(II) ions, respectively. The developed sensor exhibited a better electrochemical performance in the detection of Zn(II) and Ni(II) ions owing to the favourable host–guest interactions between the hydroxyl groups-functionalized lower rim of dicarboxyl-calix[4]arene and the metal ions. The RSD of the five independent Calix/MPA/Au electrode for Zn(II) and Ni(II) ions was calculated to be 16.3 and 16.1%, respectively. Despite the lower sensitivity of the modified electrode towards Ni(II) ions, this finding proves the high selectivity of the calixarene as a detection probe towards the fitted size of guest ion, hence promising to be assembled and explored as a solid-state based-supramolecular host molecule for tracing metal ions.

Rational effect of CuSe2 phase with octadecyl amine modified reduced graphene composite for dual-mode sensing of environmental hazardous anthelminthic drug in aquatic and biological samples

The increasing usage of antihelminthic drug mebendazole (MEB) in humans and livestock poses serious threat and is considered a significant environmental pollutant. Hence, monitoring the MEB residues in environmental samples, and human fluids is essential to decrease the ecological risk and improve the health of humans. In this work, copper selenide (CuSe2) nano/microspheres were hydrothermally synthesized and ultrasonically treated with rGO surface modified with ODA alkyl amine (rGO-ODA). The optical, structural, morphological, and functional analysis were performed which revealed the CuSe2 in marcasite phase, orthorhombic pattern with Pnnm space group, and substantial composite formation. The morphological studies revealed sphere structure of the CuSe2 and wrinkled sheets of rGO-ODA. A sensor that detects MEB using the cyclic voltammetry (CV), differential pulse voltammetry (DPV) and UV-Vis absorbance techniques was developed. For DPV analysis, the sensor exhibited a very low value for limit of detection 13.55 nM and a sensitivity of 9.4871 μA M−1cm−2. For UV-Vis, the sensor demonstrated a very low limit of detection 22.3 nM. The use of this sensor was validated in real-time analysis with aquatic and biological real samples. The results suggested > 90% of analyte recovery and enhanced efficiency for MEB detection with a potential for commercialization in future.

Scrap Gold Recovery: Recycling, Fabrication and Electrochemical Characterization of Low-Cost Gold Electrode

As a noble metal, gold is considered the most popular material in electrocatalysis. In spite of that, this metal is a highly expensive material in the manufacture of low-cost appliances. In the present work, scrap gold, produced in jewellery as waste, is introduced as a low-cost resource of gold to be recycled. A gold electrode was fabricated by connecting the tablet shaped recycled gold with copper wire inserting into a polytetrafluoroethylene (PTFE) tube. The manufactured electrodes are easily renewable, modifiable with nanomaterials and show excellent electrochemical characteristics in presence of redox species. The CV (cyclic voltammetry), DPV (differential pulse voltammetry), and EIS (electrochemical impedance spectroscopic) analysis data also infer that the developed recycled gold-based electrodes would be suitable for the development of low-cost electrocatalytic sensors devices.