A chemiluminescence biosensor based on the peroxidase-like property of molybdenum disulfide/zirconium metal-organic framework nanocomposite for diazinon monitoring

BACKGROUND

Organophosphorus pesticides are widely used in agriculture owing to their high effectiveness as insecticides. Among these, diazinon is a common environmental contaminant that acts as an acetylcholinesterase (AChE) enzyme inhibitor. As the current methods are too expensive and time-consuming for routine analysis of diazinon, its trace monitoring by rapid and sensitive methods is critical to protect the environment and human health.

RESULTS

A biosensor was introduced for the indirect detection of diazinon using a molybdenum disulfide/zirconium metal-organic framework (MoS₂@MIP-202(Zr)) nanocomposite. The probe is based on the peroxidase mimic of the prepared nanocomposite on NaHCO₃-H₂O₂ chemiluminescence system as well as the inhibitory effect of diazinon on the enzymatic activity of AChE. The chemiluminescence signal is gradually decreased with an increase in diazinon concentration, and there is a linear relationship between the analytical signal and diazinon concentration. Under the optimum conditions, the calibration plot is linear in the concentration range of 0.5-300.0 nmol L^-1. The limit of detection and quantification limit of the method are 0.12 and 0.40 nmol L^-1, respectively. The inter-day and intra-day relative standard deviations (% RSD n = 5, diazinon concentration; 100 nmol L^-1) are 3.66 and 1.35%, respectively. The method was used for diazinon detection in real water samples, and the high relative recovery values for the spiked samples along with satisfactory results of a certified reference material analysis confirmed that the method is accurate and free from the matrix effect.

SIGNIFICANCE AND NOVELTY

A nano-probe based on the peroxidase-like property of MoS₂@MIP-202(Zr) nanocomposite was developed for the first time for indirect detection of residue levels of diazinon in water samples. The high stability of the nanocomposite makes it a good alternative for natural peroxidase enzymes such as horseradish peroxidase with low stability.

Design of fluorescent method for sensing toxic diazinon in water samples using PbS quantum dots-based gelatin

In this current article, a chemical sensor was synthesized PbS functionalized with gelatin quantum dots for toxic diazinon. The measure of toxic diazinon was performed using concentration 0.5 µM, PbS quantum dot-gelatin nanocomposites sensor, pH 6, and time 50 s, wavelength 300 nm, in phosphate buffer solution. Under the optimum conditions, the detection limit linear range was obtained (0.01-20.0 µg L^-1). The standard deviation of less than (1.0%), and detection limits (3S/m) of the method (0.01 µg L^-1) and quantification (LOQ) of (0.099 µg L^-1), for determination of toxic diazinon, was obtained. The observed outcomes confirmed the suitability recovery and a very low detection limit for measuring the toxic diazinon. The Chemical PbS Quantum Dot-Gelatin nanocomposites sensor as excellent sensor was applied to measure and analyze residue toxic diazinon in water samples.

Sensitive and selective magnetic dispersive microextraction of diazinon from urine samples by molecularly imprinted polymer based on core-shell metal-organic frameworks

A core-shell magnetic metal-organic framework (Fe₃O₄ SiO₂/ PAEDTC@ MIL- 101 (Fe)) was synthesized as the substrate and then covered with a surface molecularly imprinted polymer (MIP) layer. Next, Fe₃O₄ SiO₂/ PAEDTC@ MIL- 101 (Fe) @ MIP was characterized by XRD, FT-IR, BET, VSM, TEM, and FE-SEM techniques and applied for selective, fast, and sensitive magnetic dispersive solid-phase microextraction (M-DµSPE) of diazinon from urine samples by the GC- FID detection method. The key experimental variables affecting M-DµSPE were studied and optimized by central composite design (CCD). Under optimum conditions (5 mL; sample at pH: 7.0, the mass of solid sorbent; 6 mg, extraction time; 4 min, acetonitrile as an eluent solvent; 1.5 mL, and desorption time; 3 min, and then reconstituted with 100 µL of methanol), the proposed method exhibits high sensitivity with limits of detection and quantification of 0.005 and 0.017 ng mL^-1, respectively. Excellent extraction recovery (98.5 %), wide linearity range (0.02-200000 ng mL^-1, R² > 0.992), high enrichment factors (47-53), and satisfactory precision (<6.3 % RSD) were achieved. The MIP- MOF@ M-DµSPE -GC-FID method can be used with high precision and wide linearity to extract and analyze trace levels of diazinon in real urine samples.

Study by absorption and emission spectrophotometry of the efficiency of the binary mixture (Ethanol-Water) on the extraction of betanin from red beetroot

In this paper, we intend to present a classical method of extraction and analysis of betanin from Algerian red beetroot, and to know the efficiency of the binary mixture (Ethanol-Water) on the extraction. Also, to know the betanin content of the extract obtained using optical spectroscopic methods. This dye is a natural pigment with high antioxidant power and widely used as a natural dye. In addition, the high bioavailability of this pigment reinforces its potential for future therapeutic applications. However, commercially the betanin content beet extracts never exceeds 1,2% and this molecule does not exist marketed in a more purified form, therefore it is necessary to have efficient tools for the enrichment of betanin extracts. The experimental results made in our laboratory, confirm the effectiveness of the binary mixture (Ethanol-Water) on the betanin extraction from Algerian beetroot, the yield obtained of extracted betanin pigment from red beetroot is 0,342 mg/g, when the mixture of solvents (Ethanol-Water) is used with a large quantity of water. As well as, the betanin has an absorption band varying from 480 nm to 540 nm and it has an emission band at 800 nm.

Multi-functional porous organic polymers for highly-efficient solid-phase extraction of β-agonists and β-blockers in milk

A simple, accurate, and highly sensitive analytical method was developed in this study for the determination of ten β-agonists and five β-blockers in milk. In this method, new adsorbent phosphonic acid-functionalized porous organic polymers were synthesized through a direct knitting method. The synthesis procedure of the materials and the extraction conditions (such as the composition of loading buffer and eluent) were optimized. Benefitting from the high surface area (545–804 m² g⁻¹), multiple functional framework and good porosity, the phosphonic acid-functionalized porous organic polymers showed a high adsorption rate and high adsorption capacity for β-agonists (224 mg g⁻¹ and 171 mg g⁻¹ for clenbuterol and ractopamine, respectively). The analytes were quantified by ultra-high-performance liquid chromatography coupled to high-resolution tandem mass spectrometry. It showed a good linearity (with R² ranging from 0.9950 to 0.9991 in the linear range of 3–5 orders of magnitude), with low limits of quantification ranging from 0.05 to 0.25 ng g⁻¹. The limits of detection of the method for the analytes were measured to be in the range of 0.02 to 0.1 ng g⁻¹. The recoveries of target analytes from real samples on the material were in the range of 62.4–119.4% with relative standard deviations of 0.6–12.1% (n = 4). Moreover, good reproducibility of the method was obtained with the interday RSD being lower than 11.7% (n = 5) and intraday RSD lower than 12.2% (n = 4). The proposed method was accurate, reliable and convenient for the simultaneous analysis of multiple β-agonists and β-blockers. Finally, the method was successfully applied for the analysis of such compounds in milk samples.

Novel phosphonic acid-functionalized porous organic polymers were synthesized through direct knitting method. It shows high adsorption efficiency and high adsorption capacity for multiple β-agonists and β-blockers analysis.

Green bioanalytical sample preparation: fabric phase sorptive extraction

Fabric phase sorptive extraction (FPSE) is a recently introduced sample preparation technique that has attracted substantial interest of the scientific community dealing with bioanalysis. This technique is based on a permeable and flexible substrate made of fabric, coated with a sol-gel organic-inorganic sorbent. Among the benefits of FPSE are its tunable selectivity, adjustable porosity, minimized sample preparation workflow, substantially reduced organic solvent consumption, rapid extraction kinetics and superior extraction efficiency, many of which are well-known criteria for Green Analytical Chemistry. As such, FPSE has established itself as a leading green sample preparation technology of 21st century. In this review, we discuss the principal steps for the development of an FPSE method, the main method optimization strategies, as well as the applications of FPSE in bioanalysis for the extraction of a wide range of analytes (e.g., estrogens, benzodiazepines, androgens and progestogens, penicillins, anti-inflammatory drugs, parabens etc.).

N-doped mesoporous carbon as a new sorbent for ultrasonic-assisted dispersive micro-solid-phase extraction of 1-naphthol and 2-naphthol, the biomarkers of exposure to naphthalene, from urine samples

This study aimed to optimize a new sample preparation method using N-doped mesoporous carbon sorbent for simultaneous measurement of 1-naphthol and 2-naphthol, the biomarkers of exposure to naphthalene. The samples were analyzed using high-performance liquid chromatography supplied with ultraviolet detector (HPLC-UV). N-doped mesoporous carbon sorbent was obtained via the hard template procedure. The synthesized nanosorbent was then characterized by transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and elemental analysis (CHN). The effective factors in the extraction of the studied biomarkers were examined by the Box-Behnken (BBD) methodology. Regarding the optimum conditions, the sketched calibration curve for naphthols was linear in the concentration levels of 1-600 µg L^-1 for human urine samples. The accuracy and reproducibility of the introduced method were determined using the relative recovery (RR %) and relative standard deviation (RSD %) tests on the fortified urine samples. RR% and RSD% were found to be 97.0-101.2% and 3.1-9.0%, respectively. The calculated method detection limit of the optimized procedure was 0.3 µg L^-1 and 0.5 µg L^-1 for 1-naphthol and 2-naphthol, respectively.

Rapid and sensitive detection of diazinon in food based on the FRET between rare-earth doped upconversion nanoparticles and graphene oxide

Diazinon is a typical phosphorothionate, which is widely used to prevent and control harmful organisms that endanger the agriculture productions. However, it is among the most toxic substances and can cause damage to the environment, food and human health even in very low concentrations. Hence, ultra-sensitive screening methods are urgently required for the detection of this extensively used pesticide. In this study, a rapid and sensitive fluorescence resonance energy transfer (FRET) method was developed for low concentration detection of diazinon in food. The aptamer-modified upconversion nanoparticles (Apt-UCNPs) were synthesized and conjugated with graphene oxide (GO) through π-π interaction. Due to the FRET between UCNPs and GO, the fluorescence was quenched. When diazinon was added, the aptamer preferentially bound with it, caused the separation of GO, and resulted in the enhancement of fluorescent signal. Under the optimal conditions, a wide linear detection range from 0.05 to 500 ng/mL was achieved, with a limit of detection (LOD) of 0.023 ng/mL. The proposed method was successfully applied to measure diazinon in real samples. Results showed that the proposed nanosensor offers an efficient, specific and simple approach for the detection of diazinon in food and has a high potential for food safety and quality control.

A beta-cyclodextrin-functionalized magnetic metal organic framework for efficient extraction and determination of prochloraz and triazole fungicides in vegetables samples

A β-cyclodextrin-functionalized magnetic zinc-metal organic framework (M-MOF/β-CD) was synthesized via a facile one-pot reaction. M-MOF/β-CD was used as a magnetic porous absorbent for the extraction and determination of prochloraz and three triazole fungicides in vegetable samples. M-MOF/β-CD was prepared by creating MOF layers on the surface of a Fe₃O₄-graphene oxide (GO) nanocomposite and bonding them with β-CD molecules. Characterization suggested that a 3D porous structure was formed, with M-MOF/β-CD exhibiting high superparamagnetism and a large surface area. As a new strategy, integrating MOFs with Fe₃O₄-GO could improve their water-resistance and mechanical strength by providing a rigid nanosupport interface. Combining M-MOF and β-CD resulted in excellent selective adsorption capacities for prochloraz and three triazole fungicides. The static adsorption process was evaluated and the results were in good agreement with the Freundlich model. Subsequently, M-MOF/β-CD was applied to extracting prochloraz and triazole fungicides from tomato and lettuce vegetables, followed by HPLC-MS/MS determination. The limits of detection for the above fungicides were found to be 0.25-1.0 μg/L at a signal-to-noise ratio of 3, with spiked recoveries of 74.13%-119.83%, indicating that M-MOF/β-CD was promising for application to the extraction and determination of fungicides in complex matrices.

Dispersive Matrix Solid-Phase Extraction Method Coupled with High Performance Liquid Chromatography-Tandem Mass Spectrometry for Ultrasensitive Quantification of Endogenous Brassinosteroids in Minute Plants and Its Application for Geographical Distribution Study

An ultrasensitive analysis method for quantification of endogenous brassinosteroids in fresh minute plants was developed based on dispersive matrix solid-phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry. During the dispersive matrix solid-phase extraction, plant samples were first ground with solid sorbent (dispersant) in one microcentrifuge tube and then centrifuged after adding extraction solvent and cleanup materials (another type of sorbent). Three protocols based on dispersive matrix solid-phase extraction were compared and discussed for plant samples with different matrix complexity. The choice of any protocol was a compromise of increasing purification efficiency and decreasing sample loss. Under optimized conditions, the limits of detection were 1.38-6.75 pg mL^-1 for five brassinosteroids in the oilseed rape samples. The intraday and interday precisions were in the range of 0.8%-9.8% and 4.6%-17.3%, respectively. The proposed method was successfully applied to detection of endogenous brassinosteroids in milligram oilseed rape (2.0 mg) and submilligram Arabidopsis thaliana seedlings (0.5 mg). Finally, the geographical distribution of five endogenous brassinosteroids of Brassica napus L. oilseed rape in different provinces of origin in the Yangtze River basin was described.

Simultaneous magnetic dispersive micro solid phase extraction of valsartan and atorvastatin using a CMC-coated Fe3O4 nanocomposite prior to HPLC-UV detection: multivariate optimization

In this study, a sensitive, rapid, accurate and practical procedure is established for determination of atorvastatin and valsartan from human biological fluids by dispersive micro solid phase extraction (D-μ-SPE) combined with HPLC-UV detector.

Ultrasound-Assisted Extraction of Cr from Residual Tannery Leather: Feasibility of Ethylenediaminetetraacetic Acid as the Extraction Solution

In this work, the use of ultrasound energy for chromium removal from residual tannery leather was investigated. The following parameters were evaluated: complexation temperature (60-90 °C), chromium/complexant molar ratio (1:0 to 1:6), complexation time (30-120 min), washing steps (1-14), washing temperature (25-80 °C), and washing time (1-10 min). For all evaluated conditions, chromium removal was monitored by flame atomic absorption spectrometry. The residual tannery leather after different extraction strategies were characterized using a scanning electron microscopy. For the proposed method, the optimized conditions were: 3 g of residual tannery leather to be treated, 100 mL of extraction solution (chromium/complexant molar ratio of 1:3), at 80 °C and 30 min of sonication. To complete the chromium removal, only five washing cycles (50 mL of water at 50 °C) of 3 min were required. Using these conditions, a chromium removal higher than 98% was achieved. Under the same reaction conditions, the results were compared with mechanical stirring (100 rpm), which allowed observing the significant effects of ultrasound for chromium removal. Comparing to the conventional method, the total time of the process (including extraction and washing steps) was decreased from 150 to 45 min and the water volume for the washing was reduced from 450 to 250 mL. Therefore, the proposed ultrasound-assisted process can be considered as a suitable alternative for chromium removal from residual tannery leather.

Preparation and application of guanidyl-functionalized graphene oxide-grafted silica for efficient extraction of acidic herbicides by Box-Behnken design

A highly selective and efficient extraction material was synthesized through the functionalization of guanidyl onto the graphene oxide-grafted silica via a simple chemical modification, which was designed and proposed to improve the enrichment capacity for acidic herbicides. The extraction material was confirmed by scanning electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectrometry, thermal gravimetric analyzer and zeta potential analysis. Theoretical adsorption energies, static- and dynamic-state binding experiments, and comparative experiments with various adsorbents were investigated to elucidate the adsorption mechanism. The introduction of guanidyl endowed the sorbent with stronger Lewis base property and electron-donating ability, hence, excellent extraction recoveries for acidic herbicides could be obtained. Besides, electrostatic and π-π interactions were considered as two major driving impetuses in the adsorption process. Single-factor experiment and response surface methodology were utilized for the optimization of extraction and desorption conditions. Under the optimized conditions, the wide linearities were obtained with correlation coefficients ranging from 0.9904 to 0.9980, and the method detection limits were in the range of 0.5-2 μg L^-1. The relative standard deviation values of the recoveries of five different extractions were 3.0-7.1%. Coupled with high performance liquid chromatography, the as-proposed method was successfully applied to detect five acidic herbicides in Lycium barbarum (Goji). It turned out that the proposed method provided a promising perspective for the selective extraction and determination of polar acidic compounds in complex samples.