Detection Of Methyl Parathion Research Articles

Facile synthesis of platinum-embedded zirconia/porous carbons tri-component nanohybrids from metal-organic framework and their application for ultra-sensitively detection of methyl parathion

Pt nanoparticles immobilized on zirconium oxide (ZrO2) and porous carbons (Pt/ZrO2/PCs) tri-component nanohybrids derived from Pt/ metal–organic frameworks (MOFs) were synthesized. They were prepared by using Pt/MOFs as a template. Additionally, MOFs (UiO-66, a traditional MOFs) were used as ZrO2 and carbon sources without the need of additional precursors. The formation of these composite materials was confirmed through a comprehensive characterization such as transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The Pt/ZrO2/PCs show strong affinity toward the phosphate group and highly electrocatalytic activity for nitro compound on methyl parathion (MP) molecules. The high performance is owing to the combination of unique electrocatalytic activity of Pt species, excellent conductivity of PCs, and good adsorption properties of ZrO2 crystals for MP. The proposed Pt/ZrO2/PCs tri-component nanocomposite sensor realized the ultrasensitive detection of MP with a wide linear range between 3.8 × 10−9 and 1.14 × 10−2 mM and a low limit of detection of 1.45 × 10−9 mM. Therefore, it can be developed as an effective sensing platform for the detection of MP.

Electrochemical sensing of methyl parathion on magnetic molecularly imprinted polymer

The electrochemical detection of methyl parathion in fish was performed by preconcentrating the pesticide on magnetic molecularly imprinted polymer and further readout on magneto-actuated electrode by square wave voltammetry. The magnetic molecularly imprinted polymer was synthesized by a magnetic core-shell strategy, using methacrylic acid as a functional monomer, and selected by theoretical calculation using the density functional theory (DFT). The characterization of this material was performed by SEM, TEM and XRD. Moreover, the binding capacity and selectivity towards methyl parathion was studied and compared with the corresponding magnetic non-imprinted polymer. The magneto-actuated electrochemical sensor showed outstanding analytical performance for the detection of methyl parathion in fish, with a limit of detection of as low as 1.22 × 10−6 mg L−1 and recovery values ranging from 89.4% to 94.7%. The magnetic molecularly imprinted polymer successfully preconcentrated the analyte from the complex samples and paves the way to incorporate this material in other platforms for the detection of this pesticide in the field of environmental control and food safety.

Lipase@ZIF-8 nanoparticles-based biosensor for direct and sensitive detection of methyl parathion

Organophosphorus pesticides especially p-nitrophenyl pesticides (methyl parathion) have neurotoxic effects and it is a difficult to remove organophosphorus pesticides residues from contaminated water. Present work has developed a sensitive, direct and rapid lipase@ZIF-8/chitosan/glassy carbon electrode (GCE) and lipase@amine-modified ZIF-8(An-ZIF-8)/chitosan/GCE biosensors for detection of methyl parathion. ZIF-8 and An-ZIF-8 nanoparticles which are a type of metal-organic frameworks with large surface area and high porosity have been facilely prepared under mild biocompatible conditions and used as lipase immobilization matrixes in the biosensors. The optimized lipase@ZIF-8/chitosan/GCE and lipase@An-ZIF-8/chitosan/GCE biosensors can detect methyl parathion with a wide linear range, good repeatability, recovery and limit of detection as low as 0.28 μM. The as-prepared biosensors can be stored in 0.05 M PBS (pH 7) at 4 °C and reused for at least 20 days with a retainment of at least 80% of its initial response to methyl parathion. This indicated that both ZIF-8/chitosan and An-ZIF-8/chitosan are suitable for immobilization of lipase that favors generation of p-nitrophenol from methyl parathion; and subsequent electrochemical oxidation and electron transfer of the p-nitrophenol.

Fabrication of AChE/SnO2-cMWCNTs/Cu Nanocomposite-Based Sensor Electrode for Detection of Methyl Parathion in Water

The work highlights inhibition-based Acetylcholinesterase (AChE) fabrication using composite nanomaterial comprising tin oxide nanoparticles (SnO2) and carboxylated multiwalled carbon nanotubes (cMWCNTs) for detection of pesticide methyl parathion (MP) in water samples. Working electrode AChE/SnO2-cMWCNTs/Cu exhibited high sensitivity with a linearity range of 1.0 μM to 160 μM and a minimum detection limit of 0.1 μM for MP in water. The fabricated electrode was found biocompatible and nontoxic which can be used to detect low concentrations of pesticide in water samples. The synergistic and facilitated electron transferring properties of SnO2-cMWCNTs/Cu made it an excellent support for immobilization of enzyme in sensing technology. The enzyme AChE was covalently immobilized with cMWCNTs using glutaraldehyde as crosslinking agent which has enhanced the storage stability and reusability of the method. The reusability attained was 30 times for 40 days when AChE/SnO2-cMWCNTs/Cu was stored at low temperature of 4°C. Developed sensor showed excellent analytical recovery of pesticide in water sample with negligible effect of interfering species. Also, AChE/SnO2-cMWCNTs/Cu was easily reactivated simply by varying pH of phosphate buffer. This method is fast, reliable, and accurate showing successful development of amperometric biosensor for detection of MP in water sample.

Three MOF-Templated Carbon Nanocomposites for Potential Platforms of Enzyme Immobilization with Improved Electrochemical Performance.

An efficient and facile metal-organic framework (MOF)-template strategy for preparing carbon nanocomposites has been developed. First of all, a series of metal ions, including Fe3+, Zr4+, and La3+, were respectively connected with 2-aminoterephthalate (H2ATA) to form three metal-organic frameworks (MOFs) and then three novel MOF-derived materials were obtained by annealing them at 550 °C under N2 atmosphere. The morphologies and microstructure results showed that they still retained the original structure of MOFs and formed carbon-supported metal oxide hybrid nanomaterials. Interestingly, it was found that La-MOF-NH2 and its derived materials were first reported, which had wool-ball-like structure formed by many streaky-shaped particles intertwining each other. Furthermore, these MOF-derived materials were all successfully used as effective immobilization matrixes of acetylcholinesterase (AChE) to construct biosensors for the detection of methyl parathion. Especially, [La-MOF-NH2]N2 with wool-ball-like structure not only provided more active sites of multicontents to increase AChE immobilization amount but also facilitated the accessibility of electron transfer and shorten their diffusion length on the surface of electrode. Under optimal conditions, the biosensor based on [La-MOF-NH2]N2 displayed the widest linear range of 1.0 × 10-13-5.0 × 10-9 g mL-1 and the lowest detection limit of 5.8 × 10-14 g mL-1 in three biosensors. This study illustrates the feasibility and the potential of a series of MOF-derived materials for biosensors with improved electrochemical performance.

One-step green synthesis of colloidal gold nano particles: A potential electrocatalyst towards high sensitive electrochemical detection of methyl parathion in food samples

Abstract A straightforward green fabrication of electrochemical assay for high sensitive quantitative detection of methyl parathion (organophosphate pesticide) via colloidal gold nanoparticles (AuNPs) modified glassy carbon electrode. Methyl parathion is widely known for its unpleasant functions in bio and ecological system. The synthesis utilizes tannic acid as a bi-functional reducing cum stabilizing agent under ambient temperature (25 °C). The colloidal TA@AuNPs were characterized through TEM, UV–vis, X-ray diffraction, and FT-IR spectroscopy. Fabricated TA@AuNPs/GCE assay has superior electrocatalytic activity toward MP in terms of a wide dynamic range (0.033–167.7 µM), and lower limit of detection (10.5 nM). In addition, the sensor displayed high selectivity, good reproducibility and stability. The practicality of fabricated electrode was verified through the determination of MP in various food and water samples.

A robust electrochemical sensing platform using carbon paste electrode modified with molecularly imprinted microsphere and its application on methyl parathion detection

A highly sensitive electrochemical sensor using a carbon paste electrode (CPE) modified with surface molecularly imprinted polymeric microspheres (SMIPMs) was developed for methyl parathion (MP) detection. Molecular imprinting technique based on distillation precipitation polymerization was applied to prepare SMIPMs and non-surface imprinted microspheres (MIPMs). The polymer properties including morphology, size distribution, BET specific surface area and adsorption performance were investigated and compared carefully. Both MIPMs and SMIPMs were adopted to prepare CPE sensors and their electrochemical behaviors were characterized via cyclic voltammetry and electrochemical impedance spectroscopy. Compared with MIPMs packed sensor, SMIPMs/CPE exhibits a higher sensing response towards MP with linear detection range of 1 × 10−12–8 × 10−9 mol L−1 and detection limit of 3.4 × 10−13 mol L−1 (S/N = 3). Moreover, SMIPMs/CPE exhibits good selectivity and stability in multiple-cycle usage and after long-time storage. Finally, the developed sensor was used to determine MP in real samples including soil and vegetables and only simple pretreatment is needed. The detection results were consistent with those obtained from liquid chromatography. Collectively, this newly developed sensor system shows significant potential for use in a variety of fields like food safety, drug residue determination and environmental monitoring.

A novel and high performance enzyme-less sensing layer for electrochemical detection of methyl parathion based on BSA templated Au–Ag bimetallic nanoclusters

In the present manuscript, a modified glassy carbon electrode with BSA templated Au–Ag bimetallic nanoclusters (Au–Ag@BSA/GCE) was employed for the rapid, selective and sensitive determination of methyl parathion (MP) as an enzyme-less electrochemical biosensor.

Selective and sensitive sensors based on molecularly imprinted poly(vinylidene fluoride) for determination of pesticides and chemical threat agent simulants

Abstract Molecular recognition in molecularly imprinted polymers (MIPs) is attributed to complementary binding sites with same or similar size, shape, and functionality to imprint molecules. A new selective and sensitive sensor based on molecularly imprinted poly(vinylidene fluoride) (PVDF) polymer for the detection of methyl parathion (MP), a ubiquitous highly hydrophobic pesticide that is commonly used as a simulant of chemical threat agents. The PVDF-based sensor was prepared using the molecular imprinting method with a pre-polymerized PVDF instead of traditional in-situ or post- polymerized ones to avoid harsh and tedious polymerization conditions. In addition to size and shape of the imprinted cavities, the developed PVDF-based sensors could exhibit high selectivity and sensitivity mainly due to dipole-dipole interaction, hydrophobic interaction and van der Waals interactions with the template MP molecules. The results show that the prepared PVDF-based sensor indeed showed high selectivity towards MP against other pesticides such as diethyl phosphoramidate, dicrotophos, 2,4,5-trichlorophenoxyacetic acid, and terephthalic acid achieving a limit of detection (LOD) of 68.0 nM and a limit of quantitation (LOQ) of 226.8 nM using quartz crystal microbalance as sensor platform. The specificity and selectivity of the prepared MIP were further verified with detection of the analyte in spiked vegetable samples.

Nonenzymatic electrochemical sensor based on CuO-TiO2 for sensitive and selective detection of methyl parathion pesticide in ground water

Detection of pesticides in ground water has become a very important and crucial research area due to the rapid expansion of agriculture and stringent environmental protection acts. In this paper, the as-prepared CuO-TiO2 hybrid nanocomposites were decorated on the glass carbon electrode as the nonenzymatic electrochemical nanosensor for the sensitive and selective detection of methyl parathion. The electrochemical behavior of the modified electrode was investigated by cyclic voltammetry, showing that the modified electrode can be used for methyl parathion detection. Differential pulse voltammetry was applied to evaluate methyl parathion detection ability under optimized experimental conditions, and found the modified electrode can detect methyl parathion sensitively in a wide dynamic detection range from 0ppb to 2000ppb with a lower limit of detection (LOD) of 1.21ppb. In addition, other interfering materials have no any influences on the detection of methyl parathion. Furthermore, the modified electrode has also been used for methyl parathion detection in the actual ground water samples, and showed efficient sensing ability. The electrochemical sensor developed would have great potentiality for methyl parathion sensing and provide new insights into the detection of other organophosphorous pesticides in the ground water.

Electrochemical Sensor Using Molecular Imprinting Polymerization Modified Electrodes to Detect Methyl Parathion in Environmental Media

In this research, the electrochemical sensor was fabricated based on glassy carbon electrode decorated by the reduced gold nanoparticles and molecularly imprinted polymer (MIP) on the electrode surface with methyl parathion (MP) as the template molecule. Four parameters, such as amount of gold nanoparticles, deposition time of gold nanoparticles, pH of acetate buffer solution, and extraction time of ethanol acidic solution, have been successfully determined by achieving the optimal sensor preparation. The MP in aqueous matrix can be quantitatively determined in the range of 0.05 to 15 μM with two linear equations at low and high ranges. In addition, the selectivity of the sensor as prepared toward the MP measurement is superior by comparing with similar structured compounds, such as imidacloprid and fenitrothion. This study also demonstrates that the deviation of current response from the MP in different matrix samples is negligible using MIP/Au/glassy carbon electrode sensor with recoveries ranged from 87.7 to 124.8%.

Novel Bifunctional Electrocatalyst for ORR Activity and Methyl Parathion Detection Based on Reduced Graphene Oxide/Palladium Tetraphenylporphyrin Nanocomposite

We introduce a facile, eco-friendly reduced graphene oxide/palladium tetraphenylporphyrin (RGO/Pd–TPP) nanocomposite for oxygen reduction reaction (ORR) and environmental pollutant detection. The catalytic properties of RGO/Pd–TPP toward ORR and methyl parathion (MP) reduction showed excellent performance due to the synergism between RGO and Pd–TPP. The other properties of RGO/Pd–TPP nanocomposite were characterized by various microscopic and spectroscopic techniques. The as-prepared RGO/Pd–TPP electrocatalyst was further fabricated on electrode to study the ORR activity and MP sensing. The RGO/Pd–TPP modified electrode shows higher current density and less methanol tolerance than the Pt/C electrode, which revealed that the proposed material can be used as an excellent alternative to commercial Pt/C electrode. In addition, the electrocatalytic reduction of MP on RGO/Pd–TPP/GCE was briefly investigated and achieved a good analytical performance with excellent linear range (0.1–125 μM), low detection limit ...

Acetylcholinesterase Biosensor for the Detection of Methyl Parathion at an Electrochemically Reduced Graphene Oxide-Nafion Modified Glassy Carbon Electrode

We report the fabrication of a methyl parathion (MP) biosensor based on acetyl cholinesterase (AChE) immobilized on reduced graphene oxide (ERGO)-Nafion (Nf) modified glassy carbon electrode. ERGO-Nf acts as a biocompatible immobilization matrix for AChE for the analysis of MP. Electrochemical oxidation of acetylthiocholine chloride occurs at 0.7 V vs. Ag/AgCl in phosphate buffer solution (pH 7). Various experimental parameters such as effect of scan rate, MP concentration, acetylthiocholine chloride concentration, AChE loading and incubation time have been optimized for the sensor calibration. The calibration curve of MP has been constructed using square wave voltammetry in the concentration range of 2 x 10(-9) M to 7 x 10(-7) M and the sensor shows good reproducibility and stability. The sensor is found to have an estimated detection limit of 1 x 10(-9) M. The biosensor has been applied for the determination of methyl parathion in a vegetable sample.

Electrospun zirconia-embedded carbon nanofibre for high-sensitive determination of methyl parathion

Carbon nanofibers embedded with ultrafine zirconia nanoparticles (ZrO2-CNFs) are fabricated via a new methodology. Polyvinylpyrrolidone (PVP) and polymethylmethacrylate (PMMA) binary polymers containing zirconium n-butoxide are first dissolved in dimethylformamide, and the resulting solution is electrospun and heat-treated. The tetragonal zirconia nanoparticles formed, with a size of 5±2nm in diameter, are uniformly distributed in the carbon nanofibres. Using Nafion as an additive, ZrO2-CNFs are drop-cast onto the glassy carbon electrode (ZrO2-CNF/GCE) and the modified electrode is then applied to detect methyl parathion (MP) using differential pulse voltammetry. Two linear relationships are found at the concentration ranges of 1×10−9–2×10−8g/L and 2×10−8–2×10−7g/L, with a detection limit of 3.4×10−10g/L (S/N>3). The electrospun-based ZrO2-CNF is a very promising coating material for electrochemical sensing of organophosphorus compounds.

Reduced Graphene Oxide Supported Cobalt Bipyridyl Complex for Sensitive Detection of Methyl Parathion in Fruits and Vegetables

AbstractHerein, we are described a green route to prepare reduced graphene oxide supported cobalt inorganic complex nanocomposite (GRGO/[Co(bpy)3]) (bpy=2,2′‐bipyridine) through facile and wet chemical approach. The formation of the nanocomposite was confirmed through suitable physical and chemical characterization techniques. The GRGO/[Co(bpy)3] nanocomposite was coated on the pretreated glassy carbon electrode (GCE). The GCE/GRGO/[Co(bpy)3] modified electrode has excellent electrocatalytic ability towards methyl parathion reduction, while the overpotential drops drastically to –0.18 V (vs. Ag/AgCl). Moreover, the effect of concentration, scan rate and electrolyte pH were detail studied. Besides, the linear response range was 0.05‐1700 μM and the detection limit was 0.0029 μM (S/N=3) and the sensitivity was 1.8197 μA μM−1 cm−2. Moreover, the fabricated electrode has high level of selectivity, which delivers satisfactory repeatability, reproducibility and stability. The sensing method was successfully demonstrated in real samples such as, tomato and apple samples.

A sensitive tapered-fiber optic biosensor for the label-free detection of organophosphate pesticides

A new optical biosensor for the detection of organophosphate compounds is reported. The transducing element is a non-adiabatic tapered fiber operates based on interference of propagation modes. By measuring the spectral shift of interferometric pattern, the proposed sensor shows a sensitivity as high as 2100nmRIU∧1 to bulk refractive index. By chemically activating the fiber surface with a bi-functional cross-linker, the enzyme acetylcholinesterase is immobilized on the optical probe with a kinetic rate of 0.0355min∧1. The label free detection of methyl-parathion (MPT), as an organophosphate pesticide, is achieved through online monitoring of its binding to the enzyme. Limit of detection of the biosensor is found to be as low as 2.4í10∧10M (S/N=3) for a concentration range of 10∧10M to 5í10∧5M for methyl-parathion. The tapered fiber biosensor shows highly reproducible response to pesticide and reactivating agent with the relative standard deviation (RSD) of 2.36% and 2.44% (n=6), respectively. The proposed sensor suggests a new tool for rapid, sensitive, cost-effective, and real-time screening of organophosphate pesticides.

Methyl parathion detection in vegetables and fruits using silver@graphene nanoribbons nanocomposite modified screen printed electrode

We have developed a sensitive electrochemical sensor for Organophosphorus pesticide methyl parathion (MP) using silver particles supported graphene nanoribbons (Ag@GNRs). The Ag@GNRs nanocomposite was prepared through facile wet chemical strategy and characterized by TEM, EDX, XRD, Raman, UV-visible, electrochemical and impedance spectroscopies. The Ag@GNRs film modified screen printed carbon electrode (SPCE) delivers excellent electrocatalytic ability to the reduction of MP. The Ag@GNRs/SPCE detects sub-nanomolar concentrations of MP with excellent selectivity. The synergic effects between special electrocatalytic ability of Ag and excellent physicochemical properties of GNRs (large surface area, high conductivity, high area-normalized edge-plane structures and abundant catalytic sites) make the composite highly suitable for MP sensing. Most importantly, the method is successfully demonstrated in vegetables and fruits which revealed its potential real-time applicability in food analysis.

A Porphyrin Molecularly Imprinted Biomimetic Electrochemical Sensor Based on Gold Nanoparticles and Carboxyl Graphene Composite for the Highly Efficient Detection of Methyl Parathion

A highly sensitive and selective biomimetic sensor based on zinc porphyrin molecularly imprinted Polymer microspheres (MIPMs), gold nanoparticles (AuNPs) and carboxyl graphene (CG) nanomaterials was successfully developed for direct electrochemical detection of methyl parathion (MP). The novel strategy emphasized the fabrication of a porphyrin zinc-based sensor via attaching MIPMs on AuNPs/CG nanocomposites. MIPMs was prepared by free radical polymerization using MP as the template, Zinc porphyrin as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linking reagent and azobisisobutyronitrile (AIBN) as the initiator. The introduction of AuNPs/CG significantly increased the effective electrode area, and amplified the sensor signal. The modified electrode was characterized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The parameters of the detection process were also optimized. The biomimetic sensor exhibits a much wider linear dynamic range between 1.0[Formula: see text][Formula: see text][Formula: see text]10[Formula: see text][Formula: see text]mol L[Formula: see text] and 8.0[Formula: see text][Formula: see text][Formula: see text]10[Formula: see text][Formula: see text]mol L[Formula: see text] and the limit of detection (LOD) down to 3.16[Formula: see text][Formula: see text][Formula: see text]10[Formula: see text][Formula: see text]mol L[Formula: see text] based on S/N [Formula: see text] 3. The sensor had good reproducibility, stability and selectivity for MP detection. The developed sensor was successfully employed for the detection of MP in real samples.

Graphene Oxide Nanoribbons Film Modified Screen-Printed Carbon Electrode for Real-Time Detection of Methyl Parathion in Food Samples

The increasing concerns about food safety urged the desire to develop rapid and sensitive sensors for the detection of food contaminants such as pesticides. We described a reproducible and reliable screen printed carbon electrode (SPCE) modified with graphene oxide nanoribbons (GONRs) for sensitive determination of methyl parathion. The GONRs were prepared from carbon nanotubes (CNTs) and characterized by TEM, SEM, XRD, FT-IR, Raman, impedance and electrochemical techniques. Compared with CNTs, GONRs possess rich edge chemistry and abundant functional groups, higher area-normalized edge-plane structures and chemically active sites. As a result, GONRs/SPCE exhibits significantly improved electrocatalytic ability to methyl parathion in comparison with CNTs. The sensor exhibited two linear ranges; (1) 100 nM to 100 μM with sensitivity of 1.804 μAμM−1 cm2, (2) 100 μM to 2500 μM with sensitivity of 0.8587 μAμM−1 cm2. The detection limit was 0.5 nM (S/N = 3). The combined advantages of SPCE and GONRs make this method suitable for food robust real-time food analysis. The method is successful in the determination of methyl parathion in Ugli and tomato fruits, Beetroot and Broccoli indicating its excellent practical applicability. The other advantages of the electrodes are excellent stability, repeatability, reproducibility and high selectivity.

Sensitive and Selective Electrochemical Biosensor Based on ELP-OPH/BSA/TiO2NFs/AuNPs for Determination of Organophosphate Pesticides with p-Nitrophenyl Substituent

We report herein a new electrochemical bisosensor based on elastin-like polypeptide-organophosphate hydrolase/bovine serum albumin/titanium oxide nanofibers/gold nanoparticles (ELP-OPH/BSA/TiO2NFs/AuNPs) for highly sensitive and selective, rapid, one-step determination of organophosphate pesticides (OPs) with p-nitrophenyl substituent. ELP-OPH was purified from genetically engineered Escherichia coli (E. coli) taking the advantage of thermal-triggered phase-transition of ELP. The surface morphology and crystal structure of the as-prepared ELP-OPH/BSA/TiO2NFs/AuNPs nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray Diffraction (XRD), respectively. The electrochemical properties and catalytic behavior of the as-prepared electrodes for the determination of methyl parathion were systematically investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry (i–t). During OPs detection, OP compounds were selectively adsorbed to the TiO2NFs surface due to the strong affinity of its phosphoric group with TiO2NFs, while AuNPs were employed to provide a stable interface for promoting electron transfer between biomolecules and electrodes, thus enhanced sensing performance was accomplished. Under the optimized operating conditions, the as-prepared biosensor can detect methyl parathion with a wide dynamic ranges (up to 116.4 μM), a good sensitivity of 734 μA cm−2 mM−1 and the limit of detection (S/N = 3) as low as 29 nM. Its further application for determination of methyl parathion spiked into lake water samples was also demonstrated with an acceptable stability. All these features indicate that the as-developed ELP-OPH/BSA/TiO2NFs/AuNPs/GCE holds great promise in rapid, sensitive, specific, and reliable detection of organophosphates pesticides.