Glass Carbon Electrode Research Articles

An electrochemiluminescence aptasensor based on Ru(bpy)32+ encapsulated titanium-MIL-125 metal-organic framework for bisphenol A assay.

Ultrasensitive and selective determination of bisphenol A (BPA) was achieved by a solid-state electrochemiluminescence (ECL) aptasensor. The Ti-based MOFs (MIL-125, MIL stands for Materials of Institute Lavoisier) have porous structure and large specific surface area. They were used as a carrier for Ru(bpy)32+ by a hydrothermal synthesis method. The Ru(bpy)32+ encapsulated MIL-125 (Ru(bpy)32+@MIL-125) was dropped on a glass carbon electrode (GCE) and used as working electrode. After that, the thiol-based aptamer of BPA was used to modify the working electrode by Ti-S bond. As a result of the specific binding affinity between aptamer and BPA, the ECL signal was significantly quenched. Thus, a selective electrochemiluminescence (ECL) aptasensor for BPA was developed. The ECL aptasensor based on Ru(bpy)32+@MIL-125 has a good ECL response toward detecting BPA. Under optimal conditions, the aptasensor can detect BPA in a wide linear range from 1.0 × 10-12 to 1.0 × 10-6M with an excellent determination limit of 6.1 × 10-13M (S/N= 3). The ECL aptasensor can selectively detect BPA in a mixture containing BPA interference compounds.

Carbon nanohorns enhanced electrochemical properties of Cu-based metal organic framework for ultrasensitive serum glucose sensing

Diabetes is a metabolic disease characterized by hyperglycemia, which can only be controlled by treatment at present. In order to monitor the course of diabetes, it is significantly important to develop a sensor with superior sensitivity, which can detect the glucose accurately and rapidly. In this paper, the copper-based metal organic framework (Cu-MOF) was found to have a significant electrocatalytic effect on glucose, and the synergistic effect of nanocomposite of Cu-MOF and carbon nanohorns (CNHs) was utilized to construct an effective biosensing interface for the glucose. Under the optimal conditions, Cu-MOF/CNHs modified glass carbon electrode (GCE) showed favorable electrochemical properties toward glucose in the wide range from 250 nM to 1.2 mM with a limit of detection of 78 nM (S/N = 3). Meanwhile, the Cu-MOF/CNHs/GCE was applied for the blood glucose analysis and achieved comparable results with clinical method (hexokinase method). The determination of glucose in commercial pear juice also indicated its reliability and accuracy. The proposed strategy not only provided a sensitive detection method for glucose but also paved a new way for the application of metal organic framework.

Fabrication of CuO/Cu/TiO2 nanotube arrays modified electrode for detection of formaldehyde

A CuO/Cu/TiO2 nanotube arrays (TNAs) modified electrode was fabricated by electrochemical method. Cu first deposited on TNAs electrode by a galvanostatic pulse method and CuO was prepared by in-situ oxidation copper in alkaline solution through cyclic voltammetry (CV). The effect of the cycle number of cyclic voltammograms and different substrate on the sensing performance were investigated. It was found that the optimal cycle number of CV is 100. The optimal CuO/Cu/TNAs electrode presents high sensitivity (814 μA mM−1cm−2) and wide linear range, with formaldehyde concentration from 65.0 μM to 7.80 mM, a detection limit of 25.0 μM (S/N = 3) and good repeatability, allowing prompt quantitative analysis of formaldehyde in alkaline solutions. Furthermore, compared to the glass carbon electrode (GCE) modified by a layer of CuO nanopaticles growing on the surface of Cu for the oxidation of formaldehyde, the CuO/Cu/TNAs electrode presents higher anodic oxidation current density and excellent cycling stability, showing that the CuO/Cu/TNAs electrode is more electro-active for oxidation of formaldehyde than the CuO/Cu/GCE. The prominent and stable electrocatalytic activity toward formaldehyde result from the synergistic effect between CuO/Cu and TNAs. In addition, the surface CuO nanoparticles on the CuO/Cu/TNAs electrode are more likely to form the highly active CuOOH species during oxidation process, which is the key to enhance the catalytic efficiency of CuO/Cu/TNAs electrodes.

Fabrication of SnO2 decorated graphene composite material and its application in electrochemical detection of caffeic acid in red wine

Metal oxide/graphene composite has become a promising electrode material to improve the performance of electrochemical sensor. Here SnO2 decorated graphene (SnO2-RGO) composite was facilely fabricated by a hydrothermal reduction of graphene oxide with SnCl2, and applied as active electrode material into constructing electrochemical sensor for caffeic acid (CA). The SnO2-RGO composite was characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrochemical sensor (SnO2-RGO/GCE) obtained from SnO2-RGO coating of glass carbon electrode showed excellent electrocatalytic performance for the redox reaction of CA. A linear range of 0.15–25 μM and a detection limit of 80 nM (S/N = 3) were achieved in 0.1 M phosphate buffer (pH 7.0). The present electrochemical sensor also showed high selectivity for CA, excellent reproducibility and stability. Eventually, the sensor SnO2-RGO/GCE was successfully applied for CA detection in commercial red wine samples with satisfactory recovery results.

A Novel Electrochemical Sensor Based on Electropolymerized Ion Imprinted PoPD/ERGO Composite for Trace Cd(II) Determination in Water.

A novel electrochemical sensor based on electropolymerized ion imprinted poly (o-phenylenediamine) PoPD/electrochemical reduced graphene (ERGO) composite on glass carbon electrode (GCE) was fabricated for selective and sensitive determination of trace Cd(II) in water. ERGO was first deposited on the surface of GCE by electrochemical cyclic voltammetry (CV) scanning to enhance the electron transport activity at electrode surface. The ion imprinted polymer (IIP) of imprinted PoPD was then in situ electropolymerized on ERGO via CV scanning with oPD as functional monomer and Cd(II) ions as template, following removal of the template using electrochemical peroxidation method. The obtained imprinted PoPD/RERGO composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray energy spectroscopy (EDS) for the observation of their morphologies and components. The electrochemical behavior of the imprinted PoPD/ERGO/GCE was performed by CV and SWASV. The fabricated sensor of the imprinted PoPD/ERGO/GCE showed a good selectivity toward target Cd(II) ions in the presence of other heavy metal ions. Under the optimized experimental conditions, the sensor exhibited a good linear relationship between SWASV stripping peak values and Cd(II) concentration in the range of 1 to 50 ng/mL, with the limit of detection as 0.13 ng/mL (S/N = 3). The proposed electrochemical sensor of imprinted PoPD/ERGO/GCE was successfully applied for trace Cd(II) determination in real water samples.

An electrochemical thrombin aptasensor based on the use of graphite-like C3N4 modified with silver nanoparticles.

An electrochemical aptasensor for thrombin is introduced that makes use of a nanohybrid composed of silver nanoparticles and graphite-like carbon nitride (Ag-g-C3N4). The material has a large surface and good biocompatibility. AgNPs are modified directly on the surface of g-C3N4 via chemical reduction. A glass carbon electrode (GCE) modified with Ag-g-C3N4 can immobilize a large number of amino-terminated thrombin binding aptamers (NH2-TBA) through strong Ag-N bonds. The electrochemical impedance signal of the aptasensor increases in the presence of thrombin. Under the optimal conditions and by using[Fe(CN)6]3-/4- as an electrochemical probe, the aptasensor shows a wide linear range of 100 fM - 20nM with a lower detection limit of 38 fM. The method was applied to the determination of thrombin in spiked human plasma and the recoveries fluctuated from 97.2% to 103%. Graphical abstractSchematic representation of an electrochemical aptasensor using graphite-like carbon nitride (C3N4) modified with silver nanoparticles as electrode substrate for thrombin (TB) detection.

A dual-template imprinted polymer electrochemical sensor based on AuNPs and nitrogen-doped graphene oxide quantum dots coated on NiS2/biomass carbon for simultaneous determination of dopamine and chlorpromazine

In this study, a dual template molecularly imprinted electrochemical sensor was fabricated for the simultaneous determination of dopamine (DA) and chlorpromazine (CPZ). Nitrogen-doped graphene oxide quantum dots (N-GOQDs) and gold nanoparticles (AuNPs) were deposited on a combination of biomass carbon and biomass-derived asymmetric carbon-based nanospheres decorated with NiS2 nanoparticles (NiS2/BC), and the obtained material was used to modify glass carbon electrode (GCE). The electropolymerization of nicotinamide (NA) on Au/N-GOQDs/NiS2/BC/GCE via cyclic voltammetry (CV) using NA as functional monomer and DA and CPZ as template was used to produce molecularly imprinted polymer (MIP) film. Various experimental parameters, including electropolymerization cycles, template-to-functional monomer ratio, pH value, elution time, and incubation time, were optimized. Differential pulse voltammetry (DPV) response under optimized parameters show two linear ranges for DA (0.05–8 µM and 8–40 µM), and the limit of detection (LOD) is as low as 2.8 nM (S/N = 3). CPZ had a linearity range of 0.005–2 µM with very low LOD value of 0.25 nM (S/N = 3). The prepared MIP electrochemical sensor had good reproducibility and repeatability, acceptable stability, and high selectivity for DA and CPZ. Furthermore, the sensor was used in real sample analysis of human serum, urine and pharmaceutical samples, and the result of recovery (93.9%–106.15%) and relative standard deviation (RSD) (1.5%–6.6%) indicated good practicality.

Binding of pDNA with cDNA using hybridization strategy towards monitoring of Haemophilus influenza genome in human plasma samples

Haemophilus Influenza leads to respiratory infections such as sinusitis, acute otitis media, pneumonia and bronchitis. In addition, it causes invasive infections such as cellulite, septic arthritis, and meningitis. Therefore, quick and sensitive detection of H. influenza is of great importance in medical microbiology. In this study, a novel DNA-based bioassay was developed to the monitoring of Haemophilus influenza genome in human plasma samples using binding of pDNA with cDNA. DNA hybridization strategy was used to investigation of DNAs binding. For this purpose, silver nanoparticle doped graphene quantum dots inks functionalized by D-penicillamine (Ag NPs-DPA-GQDs) were synthesized and deposited on the surface of glass carbon electrode (GCE). Also, gold nanoparticles functionalized with cysteamine (CysA-AuNPs) were deposited on the surface of the Ag-DPA-GQDs modified GCE. Afterward, thiolated DNA probe was immobilized on the surface of the modified electrode. DNA hybridization was monitored using square wave voltammetry (SWV) technique. Engineered genosensor indicated good performance with high specificity and sensitivity for detection of Haemophilus influenza genome. Under optimal conditions, linear range and low limit of quantitation (LLOQ) were obtained as target concentrations ranging from 1 pM–1 ZM and 1 ZM, respectively. The designed biosensor also showed high capability of discriminating one-base, two-base and three-base mismatched sequences. Also, the prepared genosensor could be easily regenerated and reused to evaluate hybridization process.

ZnO/CNT-COOHs based solid-state ECL sensor for tetracycline detection in fishpond water

A sensitive electrochemiluminescence (ECL) sensor in solid-state for the detection of tetracycline (TET), based on carboxylated carbon nanotubes modified ZnO (CNT-COOHs/ZnO), was developed in this research. The ZnO, which worked as luminophore here, was an environment-friendly material. Resulted from its tremendously specific surface area, the loading amount of CNT-COOHs increased. The CNT-COOHs played a role of catalyzer to enhance the ECL intensity of CNT-COOHs/ZnO modified glass carbon electrode (GCE) in triethanolamine (TEOA) contained electrolyte. After adding TET in the solution, the ECL intensity significantly quenched. The ΔECL intensity showed a good correlation to the concentration of TET in the range of 1.0 × 10–8–1.0 × 10–4 M and the detection limit achieved to 6.7 × 10–9 M within a response time of 1.0 min. Furthermore, the proposed CNT-COOHs/ZnO based ECL sensor was applied for the detection of TET in fishpond water and exhibited a good accuracy. We believe our system supplied a potential platform for the detection of TET in real world.

Facile strategy for synthesis of silver-graphene hybrid with controllable size and excellent dispersion for ultrasensitive electrochemical detection of acetamiprid

Electrochemical properties of metal-graphene hybrid depend on size and dispersion of metal nanoparticles on graphene sheets. The study reports a facile synthesis of silver-graphene hybrid with controllable size and excellent dispersion. Histidine-functionalized graphene quantum dots (His-GQDs) are firmly bound on graphene sheets of graphite oxide (GO) and then combined with Ag+ to form stable Ag/His-GQD/GO complex. Followed by heating in N2 to produce Ag/His-GQD/G. The resulting hybrid offers well-defined three-dimensional structure, in which all Ag nanoparticles are uniformly dispersed on the surface of graphene sheets. Interestingly, the size and density of Ag nanoparticles can be effectively adjusted by varying mass ratio of His-GQD/GO or Ag+/GO. To construct on the aptasensor, aptamer of acetamiprid was connected to Ag nanoparticles via Ag-S bond in the hybrid immobilized on surface of glass carbon electrode. The architecture creates an excellent catalytic activity. The aptasensor based on Ag/His-GQD/G exhibits ultrahigh sensitivity, specificity and stability for electrochemical detection of acetamiprid. A linear relationship between the peak current of differential pulse voltammetry and logarithm value of acetamiprid concentration was obtained in the range from 1.0 × 10−16 to 5.0 × 10−12 M with a detection limit of 4.0 × 10−17 M. The method has been successfully applied in detection of acetamiprid in tea.

Ultrathin exfoliated WS2 nanosheets in low-boiling-point solvents for high-efficiency hydrogen evolution reaction

Two-dimensional mono-or few-layer WS2, as a typical transition metal dichalcogenide, usually exhibits excellent electrocatalytic hydrogen evolution reaction (HER) activity. In this work, low-boiling-point solvents are adopted for the controllable preparation of ultra-thin WS2 nanosheets by an improved liquid phase exfoliation process directly from the raw WS2 powder. The thickness of as-obtained WS2 nanosheets is about ∼1.5 nm with lateral size of ∼1.2 μm. Their HER performance was investigated by loading them onto a glass carbon electrode in 0.5M H2SO4 solution. The resulting polarization and Tafel curves indicate that the as-obtained WS2 nanosheets are effective electrocatalysts for HER with a low onset potential of 65mV and a Tafel slope of 55mV/dec. The proposed liquid phase exfoliation technique is lucrative for exfoliating transition metal disulfide materials in various applications.

Electrodeposition of Three‐Dimensional Network Nanostructure PEDOT/PANI for Simultaneous Voltammetric Detection of Ascorbic Acid, Dopamine and Uric Acid

AbstractIn this study, poly(3,4‐ethylenedioxythiophene) (PEDOT) and polyaniline (PANI) were electrodeposited via cyclic voltammetry (CV) on glass carbon electrode (GCE) layer by layer. The prepared electrode (GCE/PEDOT/PANI) was used for the simultaneous sensitive determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) at different oxidation potentials. The peak distances of AA and DA, DA and UA, AA and UA were 216 mV, 104 mV, 320 mV, respectively. For individual detection of AA, DA and UA, the linear ranges were 1×10−4‐1×10−2 M, 3×10−5‐1×10−3 M and 7×10−7‐1×10−4 M with detection limits of 2.42×10−5 M, 4.58×10−6 M and 2.38×10−7 M (S/N=3), respectively. For simultaneous detection of AA, DA, and UA, the linear response ranges were 1×10−4‐1×10−3 M, 3×10−4‐1×10−2 M, and 3×10−6‐1×10−4 M with detection limits of 6.91×10−5 M, 3.66×10−5 M and 4.13×10−7 M (S/N=3), respectively. The GCE/PEDOT/PANI displayed good selectivity, reproducibility and storage stability, and was further applied to the detection of AA, DA, and UA in 5% normal human serum samples.

Electrocatalytic Oxidation and Sensitive Determination of Paracetamol Based on Nanosheets Self‐assembled Lindgrenite Microflowers

AbstractIn this work, the nanosheet‐assembled lindgrenite microflowers (chemical formula: Cu3Mo2O9) were synthesised through a simple process and low‐cost raw materials at room temperature in aqueous solution without using any surface‐active agent. The tightly interlaced nanosheets, like petals, can increase the specific surface area, which can bring about higher electrocatalytic activity and electroanalysis sensitivity. Thus, lindgrenite microflowers were prepared as an electrochemical sensor and successfully applied in the detection of paracetamol through the modified glass carbon electrode. Furthermore, this electrochemical reaction process was simulated at the ab‐initio level to reveal the catalytic mechanism, and the simulation results agreed well with electrochemical experiments. The electrochemical performance of the lindgrenite microflowers modified glassy carbon electrode (GCE) was studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The linearity of paracetamol ranged from 0.05 to 1200 μM (IT method) and 0.05 to 1000 μM (DPV method), low detection limit (0.01 μM) and high sensitivity (5.11 mA mM−1 cm−2) towards paracetamol. Moreover, this sensor was applied to detect paracetamol in human blood serum samples. The excellent results demonstrated that the prepared electrode not only showed a desirable linear range towards paracetamol but also exhibited practical applicability and reliability towards human serum samples detection.

Label-Free Electrochemiluminescence Immunosensor for the Determination of Cardiac Troponin I Using a Cadmium Sulfide–Molybdenum (IV) Sulfide Nanocomposite Modified Glassy Carbon Electrode

A label free electrochemiluminescence (ECL) immunosensor for the determination of cardiac troponin I was developed using CdS-MoS2 composites as the electrochemiluminescence emitters. The CdS-MoS2 composites were synthesized by a hydrothermal method and used for the construction of the electrochemiluminescence biosensing platform. For the fabrication of the immunosensor, CdS-MoS2 composites, chitosan, cardiac troponin I antibodies, and bovine serum albumin were consecutively assembled on the glass carbon electrode. Under the optimum conditions, the label free electrochemiluminescence determination of cardiac troponin I was obtained. Due to the excellent electrochemiluminescence performance of CdS-MoS2 composites and high specificity of the immunoreactions, the sensor shows satisfactory selectivity and high sensitivity for cardiac troponin I determination. The detection limit was 1.0 pg mL−1 and the linear range was from 5.0 pg mL−1 to 100.0 ng mL−1. Moreover, the method was successfully used to determine cardiac troponin I in human serum samples with recoveries between 85.4 and 111.0%. This label-free immunosensor possesses many merits, including a simple sensing process, good electrochemiluminescence performance of the CdS-MoS2 composites, and high flexibility for extending the strategy for the determination of other biomarkers.

Ultrasensitive amperometric immunosensor for the prostate specific antigen by exploiting a Fenton reaction induced by a metal-organic framework nanocomposite of type Au/Fe-MOF with peroxidase mimicking activity

To increase the sensitivity of electrochemical sensor, Fe-MIL-88B-NH2 (Fe-MOF) with peroxidase-like activity is designed for the construction of immunoprobe. The Fe-MOF was prepared by one-step hydrothermalf method using 2-aminoterephthalic acid and iron(III) chloride. For the immunoprobe, it was fabricated by gold nanocomposite/Fe-MOF (Au/Fe-MOF) for the immobilization of labeling antibody (the antibody was used to conjuncting with label materials). The thin layer of Methylene Blue (MB) covered by reduced graphene oxide-gold nanocomposites (Au-rGO) serves as a substrate to covalently fix coating antibodies. The MB as a redox-active species was modified on the glass carbon electrode that can give a strong amperometric signal at 0.18V (vs. Ag/AgCl). With the participation of H2O2, Fe-MOF can induce the Fenton reaction which degrades MB covered by Au-rGO on the substrate. The rest of MB on the surface of electrode becomes oxidized thereby generating acurrent signal. Square wave voltammetry (SWV) was used to quantify PSA. Under optimal conditions, the immunoassay is stable, specific and reproducible. It has a lower detection limit of 0.13pgmL-1 (S/N = 3) and awide analytical range that extendsfrom 0.001 to 100ngmL-1. Graphical abstractA sandwich-type amperometric immunoassay based on Fe-MOF-induced Fenton reaction was designed for sensitive determination of prostate specific antigen.

MOF-derived ZnCo2O4 porous micro-rice with enhanced electro-catalytic activity for the oxygen evolution reaction and glucose oxidation.

A porous ZnCo2O4 micro-rice like microstructure was synthesized via calcination of a Zn–Co MOF precursor at an appropriate temperature. The as-prepared ZnCo2O4 sample presented good electrocatalytic oxygen evolution reaction performance with a small overpotential (η10 = 389 mV) and high stability in basic electrolyte. Furthermore, in basic medium, the as-synthesized ZnCo2O4 micro-rice also showed good electrocatalytic activity for glucose oxidation. A ZnCo2O4 micro-rice modified glass carbon electrode may be used as a potential non-enzymatic glucose sensor. The excellent electrocatalytic OER and glucose oxidation performances of ZnCo2O4 might be attributed to the unique porous structure formed by the nanoparticles. The porous architecture of the micro-rice can provide a large number of electrocatalytically active sites and high electrochemical surface area (ECSA). The result may offer a new way to prepare low-cost and high performance oxygen evolution reaction and glucose oxidation electrocatalysts.

Ultrahigh electrocatalytic activity and durability of bimetallic Au@Ni core-shell nanoparticles supported on rGO for methanol oxidation reaction in alkaline electrolyte

The bimetallic Au@Ni core-shell nanoparticles (NPs) supported on reduction graphene oxide (Au@Ni-rGO) nanocomposites are synthesized for the first time in aqueous medium following a successive reduction strategy. The morphology, structure and composition of the Au@Ni-rGO nanocomposites are characterized by transmission electron microscopy (TEM), scanning TEM-high angular annular dark field (STEM-HAADF), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectrometer (EDS) and EDS-mapping. The TEM, STEM-HAADF images and EDS-mapping results demonstrate the formation of core-shell structure with Au core and Ni shell. Besides, the Au@Ni core-shell NPs directly grow on rGO support with good dispersion. From the XPS and EDS results, the Au@Ni-rGO nanocomposites consist of Au, Ni, C and O elements. The electrochemical experiments indicate that the Au@Ni-rGO/glass carbon electrode (Au@Ni-rGO/GCE) displays excellent electrocatalytic activity towards methanol oxidation reaction (MOR) in alkalic electrolyte with a highly mass activity of 1446.7 mA mg−1. Furthermore, it presents outstanding cycling stability in the MOR conditions, with the mass current retention of 87% compared with its initial value after 3 h (10800 s). The electrocatalyst also displays excellent CO tolerance in MOR process. Therefore, the Au@Ni-rGO nanocomposites offer exciting opportunities to be practical application in direct methanol fuel cells as non-Pt electrocatalyst.

Conjugated polymer self-assembled with graphene: Synthesis and electrochemical 1-hydroxypyrene sensor

Urinary 1-hydroxypyrene (1-OHP), one of the metabolite of polycyclic aromatic hydrocarbons (PAHs), has been extensively applied as a biomarker of animals and human exposure to PAHs. Herein, we synthesized a novel conjugated polymer poly-8-methoxy-7-methyl-5-(10-anthracen-9-yl)quinolone (PMMAYQ) using Suzuki coupling reaction, and then fabricated a homogeneous PMMAYQ/grahene multilayer film via layer-by-layer self-assembly technique and applied for electrochemical sensing of 1-OHP. Under the optimal conditions, {PMMAYQ-Graphene}16 modified glass carbon electrode exhibited excellent response for detection of 1-OHP. A linear range from 0.5 to 120 nM was obtained with a low detection limit of 0.07 nM (S/N = 3) and a sensitivity of 0.5539 μA/μM. The electrochemical sensor exhibited excellent stability, accepted repeatability, and good selectivity. The developed method was employed for determination of 1-OHP in human urine samples and recoveries in the range of 95.6%–107.1% were achieved.

A new voltammetric sensor based on poly(L-cysteine)/GR composite film modified electrode for the sensitive determination of amaranth in wastewater

ABSTRACT A simple voltammetric sensor was first constructed by dripping graphene (GR) on to the glass carbon electrode (GCE) and subsequently electro-polymerizing L-cysteine film. The sensor had a good voltammetric response to amaranth and linear in the range of 1.0 × 10−8–1.0 × 10−6 mol L−1. The detection limit of amaranth was 4.0 × 10−9 mol L−1 (S/N = 3). Using this method, we successfully obtained satisfactory results of amaranth in confectionery wastewater. This work promoted the potential applications of amino acid materials and GR in environmental pollution science.

Ultrasensitive non-enzymatic pesticide electrochemical sensor based on HKUST-1-derived copper oxide @ mesoporous carbon composite

Electrochemical sensors for monitoring pesticides have attracted great interest recently. Herein, we report a novel strategy to fabricate an ultrasensitive non-enzymatic pesticide sensor based on glass carbon electrode (GCE) modified by copper oxide @ mesoporous carbon (CuOx@mC) composite derived from directly pyrolysing metal–organic framework HKUST-1. The formation of CuOx@mC composite was confirmed by multiple characterization techniques. The CuOx@mC composite showed better electrochemical response towards glyphosate than HKUST-1 did, which may be attributed to its mesoporous structure and improved conductivity after heat treatment. The electrochemical measurements demonstrated that the CuOx@mC/GCE displayed superior sensing performances, giving an ultralow detection limit of 7.69 × 10−16 M toward glyphosate over the linear range of 1.0 × 10-15 to 1.0 × 10-4 M. The sensor also showed good reproducibility, stability and excellent anti-interference ability. Furthermore, the sensor was applied to detect glyphosate in real fruits samples and received satisfactory results and excellent recoveries.