High Sensitive Electrochemical Sensor Research Articles

Revolutionising pesticide detection: a high-sensitivity electrochemical sensor with CdS/g-C3N4/MWCNTs for paraquat monitoring

ABSTRACT Over a decade, the Malaysia National Poison Centre found that 40% of pesticide poisoning cases may be linked to excessive paraquat (PQ) in water, soil, or food, underscoring the widespread impact on public health and emphasising the importance of detecting even trace amounts of PQ residues in the environment. Thus, this study presents a novel electrochemical sensor based on multiwalled carbon nanotubes (MWCNTs) reinforced cadmium sulphide co-anchoring on graphitic carbon nitride (CdS/g-C3N4) nanocomposites for PQ detection. The CdS/g-C3N4 nanocomposite was successfully synthesised and characterised through FTIR, XRD, EDX, FESEM and TEM analysis. The modified electrode (CdS/g-C3N4/MWCNTs PE) exhibited improved electrocatalytic activity, as demonstrated by cyclic voltammetry (CV) and impedance spectroscopy. The CdS/g-C3N4/MWCNTs PE displayed a high CV peak and low Rct value which corresponded to a higher electron transfer rate, reduced charge transfer resistance and enhanced mass transport properties. The electrochemical sensor’s performance was evaluated for the detection of PQ, and it demonstrated a linear response in a range of 1.0 µM to 0.1 mM with a limit of detection of 0.14 μM. Furthermore, the sensor exhibited selectivity with a less than 16% potential interference from various organic chemicals and inorganic ions. The sensor’s applicability was tested by quantifying PQ in real water samples, showing excellent recovery percentages ranging from 98.9% to 102.0%. The developed electrochemical sensor provides a practical solution for the rapid and accurate monitoring of PQ levels in the environment. This work establishes the foundation for the development of a selective electrochemical sensor for pesticide analysis, addressing both public health and environmental concerns.

Disposable and Sensitive Electrochemical Determination of Isoliquiritigenin in Licorice Using Screen-Printed Carbon Electrode Modified With Multi-Walled Carbon Nanotubes

Herein, a high-sensitive electrochemical sensor based upon a multi-walled carbon nanotubes modified screen-printed carbon electrode (MWCNTs-SPCE) was constructed for the determination of isoliquiritigenin (ISL). The electrochemical properties of ISL on the MWCNTs-SPCE were investigated systematically and a fast and cost-effective method for the determination of ISL was successfully established. A clear irreversible oxidation peak of the ISL was observed at 0.3 V (versus Ag/AgCl) on the MWCNTs-SPCE. The oxidation of ISL on MWCNTs-SPCE was an adsorption reaction accompanied by diffusion. Using differential pulse voltammetry (DPV), we observed that the oxidation peak current of the ISL in phosphate buffer (pH 7) showed a linear relationship from 0.50 to 100 µg/mL and a detection limit of 0.10 µg/mL. This method displayed good repeatability and stability, as well as exhibited excellent selectivity for ISL. Also, we successfully applied the method to determine ISL in Chinese herbal medicine licorice. Validation of the analyses via spike assays showed a recovery rate ranging from 95.39 to 101.00%, which was consistent with high performance liquid chromatography (HPLC).

High-sensitivity electrochemical sensor using no nanomaterials for the detection of ciprofloxacin with poly 2-(hydroxymethyl)thiophene-modified glassy carbon electrode

High-sensitivity electrochemical sensor using no nanomaterials for the detection of ciprofloxacin with poly 2-(hydroxymethyl)thiophene-modified glassy carbon electrode

Optimization of arsenic detection conditions using copper ferrite nanocomposite in aqueous medium via response surface methodology

Arsenic (As) element is considered a toxic and carcinogenic pollutant in the environment. Therefore, effective technology for its detection in drinking water is crucial. In this study, a modified electrode with copper ferrite and multiwall carbon nanotubes (MWCNTs) has been used as a simple, high-sensitivity electrochemical sensor for detection of As(III) ion in water. After preparation of the modified electrode, the electrochemical behavior of arsenic was investigated by voltammetric technique. The prepared nanostructures were characterized by different techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopes (FESEM), and electrochemical impedance spectroscopy (EIS). The effects of chemical and instrumental variables on the process efficiency were evaluated through multivariate optimization. The optimal conditions were obtained at pH = 5.00, modifier percentage 18.37 %, time 52.53 s, scan rate 0.062 Vs−1, and pulse height 0.036 V. Thus, the modified electrode with copper ferrite and MWCNTs nanostructures can be used for sensitive detection of arsenic in water samples under the optimal conditions designed through response surface methodology (RSM).

A highly sensitive electrochemical sensor by growing Ag nanoparticles on the surface of PPy@PEDOT:PSS film for detecting sodium hydroxymethanesulfinate molecules.

A high-sensitivity electrochemical sensor was fabricated via in situ growth of Ag nanoparticles (AgNPs) on the surface of a polypyrrole@poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PPy@PEDOT:PSS) film for detecting sodium hydroxymethanesulfinate (SHF) molecules in milk and rice flour samples. The sensor fabrication process involved randomly decorating Ag seed points on the porous PPy@PEDOT:PSS film via a chemical reduction process using a AgNO3 solution. Next, AgNPs were anchored on the PPy@PEDOT:PSS film surface using an electrochemical deposition method to prepare a sensor electrode. Under optimal conditions, the sensor exhibits a good linear relation within a range of 1-130ng/mL for real milk and rice flour samples and its limit-of-detection values were up to 0.58 and 0.29ng/mL, respectively. Additionally, Raman spectroscopy was used to identify the byproducts of the chemical reaction, such as formaldehyde. This AgNP/PPy@PEDOT:PSS film-based electrochemical sensor offers a simple and rapid method for detecting SHF molecules in food products.

High performance self-supported nickel oxalate/polyaniline electrode: a novel high sensitivity electrochemical ammonia sensor

High performance self-supported nickel oxalate/polyaniline electrode: a novel high sensitivity electrochemical ammonia sensor

Simultaneous determination of citalopram and selegiline using an efficient electrochemical sensor based on ZIF-8 decorated with RGO and g-C3N4 in real samples

A novel carbon paste electrode (CPE) modified with ZIF-8/g-C3N4/RGO nanocomposite is used as a high sensitive electrochemical sensor to simultaneously determine citalopram (CIT) and selegiline (SEL). Simultaneous determination of these drugs is important because of their effect on the level of neurotransmitter serotonin in the central nervous system (CNS) which can happen by overuse and concurrent consumption. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) are used in order to investigate the electrochemical behavior of the electrode. Various techniques such as scanning electron microscopy (SEM) with energy dispersive x-ray analysis (EDX), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) are employed to affirm the structure of ZIF-8/g-C3N4/RGO nanocomposite. Excellent sensing performance of the suggested electrode is verified based on the low limit of detection of 0.008 μM and 0.014 μM which represent two linear ranges from 0.009 to 900 μM for CIT and 0.09–900 μM for SEL, respectively. The analytical performance of the proposed electrochemical sensor is investigated in real samples including human blood and urine with acceptable results.

A High-Sensitive and Durable Electrochemical Sensor Based on Geobacter-Dominated Biofilms for Heavy Metal Toxicity Detection

A High-Sensitive and Durable Electrochemical Sensor Based on Geobacter-Dominated Biofilms for Heavy Metal Toxicity Detection

Detection of pesticide using Cu-rGO modified electrochemical sensor

The increased population of the world has intensified the demand for food, which escalates the use of pesticides in agricultural fields. The pesticides contaminate food, soil, and water bodies. The present article focuses on the detection of pesticides in runoff water from agricultural fields. In this study, a high sensitive electrochemical sensor for detection of organophosphate with the help of Cu-rGO nanocomposite. Cu-rGo was synthesized using the co-precipitation method and GO was synthesized using modified hummer’s method. The scanning Electron microscope, X-ray diffraction, and Raman spectroscopy confirmed the successful synthesis of the nanocomposite. The surface morphology of the nanocomposite was obtained from SEM analysis. Cyclic voltammetry and differential pulse voltammetry was performed using corrtest Potentiostat (CS 350) and a three-electrode setup for determination of electrochemical behavior of Cu-rGO nanocomposite and its interaction with malathion. Cu-rGO nanoparticles were deposited on the surface of a glassy carbon electrode and used as a working electrode and Ag/AgCl electrode as reference electrode and platinum wire as the counter electrode was used for detection of pesticide. Altogether, Cu-rGO modified electrode produced a very good result for the determination of pesticide in runoff water samples of agricultural fields.

Sensitivity enhancement in rGO/Mn3O4 hybrid nanocomposites: A modified glassy carbon electrode for the simultaneous detection of dopamine and uric acid

A high sensitive electrochemical sensor was designed for the real time detection of dopamine (DA) and uric acid (UA) by using the Nanocomposite (NC) of reduced graphene oxide nano-octahedral shaped Mn3O4 modified Glassy Carbon Electrode (rGO/Mn3O4/GCE). The effect of Mn3O4 on the electrochemical and physical properties of rGO/Mn3O4 NC by Mn3O4 contents was analyzed by varying the molar ratio of Mn precursor (1, 5 and 10 mM denoted as GM1:1, GM1:5 and GM1:10 respectively). Due to the unique morphology and physical properties originated from Mn3O4, GM1:10/GCE revealed enhanced electrochemical response in terms of large peak potential separation, high selectivity and sensitivity. The GM1:10/GCE displayed a distinct SWV response to DA and UA for 1–600 μM at lowest detection limit of 1.42 μM and 0.76 μM. Additionally, anti-interference property of the designed sensor against electroactive molecules is found to be excellent stability and good reproducibility. Finally, it was make use for the detection of DA and UA in the pharmaceutical compound and physiological residue.

Design a high sensitive electrochemical sensor based on immobilized cysteine on Fe3O4@Au core-shell nanoparticles and reduced graphene oxide nanocomposite for nitrite monitoring

Modification of glassy carbon electrode (GCE) using cysteine immobilized Fe3O4@Au core-shell nanoparticles (Fe3O4@Au@Cys) and reduced graphene oxide (rGO) nanocomposite has been offered to fabricate a nitrite-sensitive electrochemical sensor. The offered sensor (Fe3O4@Au@Cys/rGO/GCE) depicted the catalytic effect toward nitrite (NO2−) monitoring using voltammetric methods. The techniques of field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and electrochemical impedance spectroscopy (EIS) were applied to recognize the morphology and structure of the prepared nanocomposite. This sensor depicted an excellent electrocatalytic response for NO2− detection under optimized conditions. Two linear segments in the calibration plot have been obtained in the range of 0.03–344 and 344–2215 µM with the limit of detection (LOD) 8 nM. The prepared sensor results for the quantitative measurement of NO2− in human serum, urine, and water were admissible. The fabricated sensor in all evaluations illustrated high stability and reproducible demeanor. The analytical results were determined and compared with the reported results of a similar method in the literature.

High sensitive electrochemical sensor for imatinib based on metal-organic frameworks and multiwall carbon nanotubes nanocomposite

A new sensitive electrochemical sensor has been constructed based on glassy carbon electrode (GCE) modified by nanocomposite of multiwall carbon nanotubes (MWCNTs) and metal–organic frameworks of copper (CuMOFs). The voltammetric response of the offered sensor (CuMOFs-MWCNTs/GCE) exhibited the catalytic effect toward imatinib (IMB). To characterize the structure and morphology of the constructed sensor, the procedures of electrochemical impedance spectroscopy (EIS) and field emission scanning electron microscopy (FE-SEM) were applied. The porosity of CuMOF was described by Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) technique. This sensor depicted an excellent electrocatalytic response for IMB detection under optimized conditions of solution pH, scan rate, accumulation potential, and time. Two linear segments in the calibration plot have been obtained for ranges of 0.01–20 and 20–220 µM with the limit of detection (LOD) 4.1 nM. The prepared sensor results were acceptable for the quantitative measurement of IMB in human blood serum (HBS), urine, and pharmaceutical dosage (Tablet), and it compared well with the reported HPLC method.Finally, the fabricated sensor demonstrated an acceptable accuracy, reproducible behaviour, and also, high stability in all electrochemical evaluations. Besides, analytical parameters were determined, and the results were compared with the reportages of similar methods.

A high sensitivity electrochemical sensor based on a dual-template molecularly imprinted polymer for simultaneous determination of clenbuterol hydrochloride and ractopamine.

A nitrogen-doped Fe-MOF shows a high specific surface area and excellent electrical conductivity after high temperature carbonization. A novel electrochemical sensor based on a N@Fe-MOF@C loaded dual-template molecularly imprinted polymer (DTMIP) modified glassy carbon electrode (GCE) was proposed for the rapid and ultra-sensitive simultaneous detection of clenbuterol hydrochloride (CLB) and ractopamine (RAC). N@Fe-MOF@C combined with a MIP significantly enhanced the electrical signal. Cyclic voltammetry (CV) was used to detect CLB and RAC. The electrochemical polymerization was conducted with O-phenylenediamine as the functional monomer and CLB and RAC as template molecules. The factors affecting the sensor response were optimized. Under the optimal experimental conditions, the CV current response showed a linear range of 10-12-8 × 10-9 M for both CLB and RAC, and the detection limit (LOD) for both CLB and RAC was 3.03 × 10-13 M (S/N = 3). This electrochemical sensing system has high sensitivity, selectivity, excellent reproducibility, repeatability and stability. The recoveries of the actual samples (97.4%-101.2%) and reasonable relative standard deviations (RSDs) (1.06%-3.17%) indicate the practicability of the sensor system. The system has high application value in the rapid detection of CLB and RAC in clenbuterol hydrochloride tablets, human urine and raw pork.

WITHDRAWN: Graphene oxide/NiO nanoparticle composite-ionic liquid modified carbon paste electrode for selective sensing of 4-chlorophenol in the presence of nitrite

In this study, a high sensitive electrochemical sensor for 4-chlorophenol (4-CP) was established based on graphene oxide NiO/NPs-ionic liquid (IL) (n-hexyl-3-methylimidazolium hexafluoro phosphate) carbon paste electrode. The proposed sensor exhibited strong enrichment effect on 4-CP and gave superior catalytic activity towards the electro-oxidation of 4-CP. On the other hand, the novel sensor was used for determination of 4-CP in the presence of nitrite for the first time. The anodic peaks of 4-CP and nitrite in their mixture can be well separated. At pH 7.0 the two peaks are separated ca. 0.57 and 0.82 V, respectively. Applying square wave voltammetry (SWV), a good linear relationship of the oxidation peak current with respect to concentration of 4-CP cross the range of 1.0–550.0 μM was achieved. The detection limit was evaluated about 0.7 μM. The novel sensor has been successfully applied for the assay of 4-CP in real samples.

NiCl(OH) nanosheet array as a high sensitivity electrochemical sensor for detecting glucose in human serum and saliva

The NiCl(OH) nanosheet array grown in situ on the carbon cloth (NiCl(OH) NS/CC) was synthesized using only anhydrous ethanol and NiCl2·6H2O as a raw material in a mild hydrothermal method. In this paper, NiCl(OH) NS/CC was used as the working electrode for electrochemically sensing glucose under alkaline conditions. Compared with some reports of nickel-based electrochemical detection of glucose, the NiCl(OH) NS/CC electrochemical sensor demonstrates a high sensitivity of 8052.0 μA mM−1 cm−2, a wide linear range of 0.001–3.45 mM, a lower detection limit of 0.29 μM and a response time of less than 5 s. In addition, our sensors can effectively detect glucose in serum and saliva of human beings. Furthermore, the NiCl(OH) NS/CC catalyst has good long-term stability and is highly selective for glucose detection.

Facile Synthesis of Protonated Carbon Nitride/Ti3C2Tx Nanocomposite for Simultaneous Detection of Pb2+ and Cd2+

A high-sensitivity electrochemical sensor for heavy metal ions (HMIs) was prepared by associating Ti3C2Tx with protonated carbon nitride (H–C3N4/Ti3C2Tx). Due to the electrostatic interaction, massive H–C3N4 was distributed on the surface of Ti3C2Tx and served as coating material. H–C3N4/Ti3C2Tx composite showed great conductivity derived from Ti3C2Tx, and H-C3N4 was with abundant electroactive deposition sites for the deposition of HMIs. In addition, the stability of H–C3N4/Ti3C2Tx composite was enhanced due to the protective H–C3N4 coating. The H–C3N4/Ti3C2Tx electrode exhibited remarkable sensitivities for the simultaneous detection of Cd2+ (0.05 ∼ 1.50 μM) and Pb2+ (0.05 ∼ 1.50 μM) and the detection limit of Cd2+ and Pb2+ were 0.001 and 0.0006 μM, respectively. Notably, sensor based on H–C3N4/Ti3C2Tx composite showed excellent selectivity for Cd2+ and Pb2+ in the presence of interfere ions and molecules (K+, Na+, Ca2+, Hg2+, Cr2+, Cu2+, Cl−, NO3−, PO4−, ascorbic acid, uric acid, acetaminophen, glucose and nicotinamide). Besides that, distinguished stability and reproductivity of H–C3N4/Ti3C2Tx electrode indicate that this sensor is promising for HMIs in wastewater and other commercial applications.

Novel nanomaterial of porous graphene functionalized black phosphorus as electrochemical sensor platform for bisphenol A detection

The porous graphene functionalized black phosphorus composite (PG-BP) was successfully synthesized via strong coherent coupling between porous graphene surface plasmons and anisotropic black phosphorus localized surface plasmons by the method of penetration of infrared ray using infrared drying. And it was used to fabricate a novel high-sensitive electrochemical sensor for determination of bisphenol A (BPA) in daily use and biological samples. The PG-BP had been characterized by infrared spectroscopy, Raman, X-ray photoelectron spectroscopic, scanning electron microscopy and energy dispersive spectrometer, indicating that PG-BP with the large specific surface area and good electrical conductivity was successfully prepared. In addition, electrochemical properties of the modified materials are comparably explored by means of impedance spectroscopy and cyclic voltammograms. Under the optimal conditions, BPA was determined quantitatively using differential pulse voltammetry. The results showed that the BPA detection current has a good linear relationship in the range of 4.3×10−8–5.5×10−5mol/L with a detection limit of 7.8×10−9mol/L (S/N=3). Results from the present work illustrate the prominent performance of PG-BP as a sensing channel for BPA sensor application and the huge potential of PG-BP as an electrode material.

Voltammetric Determination of Acetaminophen and Tryptophan Using a Graphite Screen Printed Electrode Modified with Functionalized Graphene Oxide Nanosheets Within a Fe3O4@SiO2 Nanocomposite.

A high sensitive electrochemical nanostructure sensor based on graphene oxide/Fe3O4@SiO2 nanocomposite modified graphite screen printed electrode (GO/Fe3O4@SiO2/SPE) has been developed for trace analysis of acetaminophen. The electrochemical study of the modified electrode, as well as its efficiency for simultaneous voltammetric oxidation of acetaminophen and tryptophan is described. Compared with bare SPE the GO/Fe3O4@SiO2/SPE exhibited excellent electrocatalytic activity toward the oxidation of acetaminophen. The plot of catalytic current versus acetaminophen concentration showed a linear segment in the concentration range 0.5 to 100.0 µM. The detection limit of 0.1 µM was obtained using calibration plot. Also the anodic peaks of acetaminophen and tryptophan in their mixture can be well separated. The GO/Fe3O4@SiO2/SPE has been successfully applied and validated by analyzing acetaminophen and tryptophan in urine and pharmaceutical samples.

Direct Electrodeposition to Fabricate 3D Graphene Network Modified Glassy Carbon Electrode for Sensitive Determination of Tadalafil

In this work, pulse potential method (PPM) was presented to fabricate directly three-dimensional graphene (3DG) network on the surface of glassy carbon electrode (GCE). The morphological characteristic of 3DG network were investigated by means of Raman spectra, scanning electron microscopy (SEM) and electrochemical experiments. The 3DG network as a new voltammetric material was used to develop a high-sensitive electrochemical sensor for determination of tadalafil. Electrochemical tests showed that the 3DG network can help to enhance response due to the large accessible surface area as well as its excellent conductivity. Under the optimum conditions, the electrochemical response showed a linear relationship with tadalafil concentrations in the range of [Formula: see text]–[Formula: see text][Formula: see text]mol[Formula: see text]L[Formula: see text], and a low detection limit of [Formula: see text][Formula: see text]mol[Formula: see text]L[Formula: see text] was achieved for tadalafil. Moreover, the fabricated electrochemical sensor exhibited excellent selectivity, stability, reproducibility and repeatability, which make it very suitable for analytical applications for the trace level determination of tadalafil.

A novel electrochemical sensor for detecting hyperin with a nanocomposite of ZrO2-SDS-SWCNTs as decoration

A novel high-sensitive electrochemical sensor with glassy carbon electrode (GCE) as support for hyperin determination is successfully designed and constructed, and the well-shaped nano-meter modified material is synthesized via a one-step and facile route. Functionalized with surfactant sodium dodecyl sulfate (SDS), Single-Walled Carbon Nanotubes (SWCNTs) are synchronously grafted with ZrO2 nanoparticles to develop into the as-prepared nano-composite (ZrO2-SDS-SWCNTs). Compared to the previous reports related with hyperin detection, the linear range gets wider and detection limit (LOD) becomes lower with the aid of this novel nano-composite modified glassy carbon electrode (ZrO2-SDS-SWCNTs/GCE). The crystalline phases and functionalization of the preparation process has been investigated by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) instrument analysis, respectively, and the micro-morphology of related modified materials is also visibly characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). In addition, electrochemical properties of the modified materials are comparably explored by means of impedance spectroscopy (EIS) and cyclic voltammograms (CV). According to the established calibration curve under optimized condition, the peak current (Differential pulse voltammetry (DPV) signal) keeps a linear relationship with hyperin concentration in the ranges of 1.0 × 10−9 − 3.0 × 10−7 mol L−1, meanwhile detection limit reaches as low as 5 × 10−10 mol L−1 (S/N = 3). As for practical applications, the proposed sensor has also worked well on sensitive hyperin determination in real species Abelmoschus manihot.