Differential Pulse Voltammetry Analysis Research Articles

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.

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.

Ultrasonic fabrication of neodymium oxide@titanium carbide modified glassy carbon electrode: An efficient electrochemical detection of antibiotic drug nitrofurazone

BackgroundPharmaceutical wastes have become a worldwide issue of environmental pollution due to even a low concentration of pharmaceuticals in the environment which has more adverse effects on wildlife and human health. Among the various pharmaceutical drugs, the antibiotic drug nitrofurazone (NZ) is harmful to public health due to cariogenic, mutagenic, and genotoxic behavior. Hence, the detection of NZ is essential for the ecosystem. MethodsHerein, we demonstrate the facile ultrasonic method to synthesize neodymium oxide@ titanium carbide (NdO@TC) electrocatalyst for the detection of NZ. The as-synthesized materials were confirmed through the XRD, FTIR, FESEM, HRTEM, EDX, and XPS analysis. Furthermore, the electrochemical behaviors were evaluated by using CV and DPV analysis. Significant findingsThe hybrid of NdO@TC coated on a glassy carbon electrode (GCE), shows prominent electrochemical detection of NZ owing to low charge transfer resistance and large surface area phenomena. Moreover, the differential pulse voltammetry (DPV) endows an excellent limit of detection (2.7 nm), sensitivity (0.1914 µA µM−1 cm−2), and a wide linear range of 0.01-2231 µM towards NZ detection. The fabricated electrode was practically utilized for the NZ determination in human urine, blood serum, and tap water samples to reveal adequate recovery results.

Electrocatalysis of 2,6-Dinitrophenol Based on Wet-Chemically Synthesized PbO-ZnO Microstructures

In this approach, a reliable 2,6-dinitrophenol (2,6-DNP) sensor probe was developed by applying differential pulse voltammetry (DPV) using a glassy carbon electrode (GCE) decorated with a wet-chemically prepared PbO-doped ZnO microstructures’ (MSs) electro-catalyst. The nanomaterial characterizing tools such as FESEM, XPS, XRD, UV-vis., and FTIR were used for the synthesized PbO-doped ZnO MSs to evaluate in detail of their optical, structural, morphological, functional, and elemental properties. The peak currents obtained in DPV analysis of 2,6-DNP using PbO-doped ZnO MSs/GCE were plotted against the applied potential to result the calibration of 2,6-DNP sensor expressed by ip(µA) = 1.0171C(µM) + 22.312 (R2 = 0.9951; regression co-efficient). The sensitivity of the proposed 2,6-DNP sensor probe obtained from the slope of the calibration curve as well as dynamic range for 2,6-DNP detection were found as 32.1867 µAµM−1cm−2 and 3.23~16.67 µM, respectively. Besides this, the lower limit of 2,6-DNP detection was calculated by using signal/noise (S/N = 3) ratio and found as good lowest limit (2.95 ± 0.15 µM). As known from the perspective of environment and healthcare sectors, the existence of phenol and their derivatives are significantly carcinogenic and harmful which released from various industrial sources. Therefore, it is urgently required to detect by electrochemical method with doped nanostructure materials. The reproducibility as well as stability of the working electrode duration, response-time, and the analysis of real environmental-samples by applying the recovery method were measured, and found outstanding results in this investigation. A new electrochemical research approach is familiarized to the development of chemical sensor probe by using nanostructured materials as an electron sensing substrate for the environmental safety (ecological system).

Fluorescent carbon quantum dots as a novel solution and paper strip-based dual sensor for the selective detection of Cr(VI) ions

Herein, we report the development of a simple green methodology to fabricate N-doped carbon quantum dots (N-CQDs) with a high luminescence using R. graveolens leaves following the hydrothermal method. Optical, chemical, morphological, and electrochemical properties were thoroughly investigated employing a variety of analytical techniques. The fabricated N-CQDs have a spherical shape, with an average diameter of 4.5 nm. Excitation dependent emission behaviour, 18% QY and green fluorescence were all observed in the N-CQDs. They are particularly resistant to various impacts such as ionic strength, pH, continuous visible light irradiation, and storage time. Since Cr(VI) ions are highly carcinogenic and mutagenic, there is an urgent demand for sensitive, selective, and efficient sensors for monitoring and measuring the amount of Cr(VI) ion in water in the environment. Hence, we developed the prepared N-CQDs as a label-free fluorescence and electrochemical probe for detecting Cr(VI) ions selectively and sensitively in aqueous solutions. Relying on static quenching together with the inner filter effect, N-CQDs performed exceptionally well as fluorescence sensors for Cr(VI) ions. The N-CQDs exhibit a limit of detection of 300 and 5 nM in the photoluminescence and differential pulse voltammetry analysis, respectively. The detection of Cr(VI) ions in real water samples using the developed sensor through both methods presented high precision without any interference. In addition, we also developed paper sensing strips for field application by depositing N-CQD on filter paper, which has been satisfactorily evaluated for sensing Cr(VI) in solid-state and solution mediums.

Carbamazepine degradation and genome sequencing of a novel exoelectrogen isolated from microbial fuel cells

Extracellular electron transfer and pharmaceutical products degradation mechanisms of electrochemical active microbial are helpful in optimizing electricity generation and biotoxic contaminants removal for microbial fuel cells (MFCs). An exoelectrogenic bacterial strain (designated as LYK-6) capable of degrading carbamazepine was first isolated from MFCs operated with carbamazepine as unique fuel. The strain LYK-6 was identified as the member of Pseudomonas genus according to morphological characteristics and 16S rRNA gene sequence analysis. Carbamazepine degradation rate of the strain LYK-6 was determined as 56.28% in inorganic salt medium using carbamazepine as sole carbon source. There were two oxidation peaks located at −0.044 V and 0.288 V revealed with differential pulse voltammetry analysis of the strain LQK-6. The maximum voltage of MFCs inoculated the strain LYK-6 reached to 187 mV when the MFCs fed with carbamazepine. The complete genome of the strain LYK-6 was of 4,454,672 bp in length and encoding 4209 protein genes. Genome annotation and functional gene analysis showed that the strain LYK-6 had significant genes encoding proteins responsible for the degradation of carbamazepine. The results demonstrated that the strain LYK-6 was promising application for the treatment of carbamazepine contaminant water by MFCs. This finding increases the known diversity of exoelectrogens.