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Sensors (Basel, Switzerland) Dec 2021Organophosphates (OPs) are neurotoxic agents also used as pesticides that can permanently block the active site of the acetylcholinesterase (AChE). A robust and...
Organophosphates (OPs) are neurotoxic agents also used as pesticides that can permanently block the active site of the acetylcholinesterase (AChE). A robust and sensitive detection system of OPs utilising the enzyme mimic potential of the cysteamine capped gold nanoparticles (C-AuNPs) was developed. The detection assay was performed by stepwise addition of AChE, parathion ethyl (PE)-a candidate OP, acetylcholine chloride (ACh), C-AuNPs, and 3, 3', 5, 5'-tetramethylbenzidine (TMB) in the buffer solution. The whole sensing protocol completes in 30-40 min, including both incubations. The Transmission Electron Microscopy (TEM) results indicated that the NPs are spherical and have an average size of 13.24 nm. The monomers of C-AuNPs exhibited intense catalytic activity (nanozyme) for the oxidization of TMB, revealed by the production of instant blue colour and confirmed by a sharp peak at 652 nm. The proposed biosensor's detection limit and linear ranges were 5.8 ng·mL and 11.6-92.8 ng·mL, respectively, for PE. The results strongly advocate that the suggested facile colorimetric biosensor may provide an excellent platform for on-site monitoring of OPs.
Topics: Acetylcholinesterase; Biosensing Techniques; Colorimetry; Cysteamine; Gold; Metal Nanoparticles; Organophosphates; Pesticides
PubMed: 34884060
DOI: 10.3390/s21238050 -
Environmental Research May 2024Pesticide exposure has been linked to some autoimmune diseases and colorectal cancer, possibly via alteration of gut microbiota or other mechanisms. While pesticides...
BACKGROUND
Pesticide exposure has been linked to some autoimmune diseases and colorectal cancer, possibly via alteration of gut microbiota or other mechanisms. While pesticides have been linked to gut dysbiosis and inflammation in animal models, few epidemiologic studies have examined pesticides in relation to inflammatory bowel disease (IBD).
OBJECTIVES
We evaluated use of pesticides and incident IBD in 68,480 eligible pesticide applicators and spouses enrolled in the Agricultural Health Study.
METHODS
Self-reported IBD cases were identified from follow-up questionnaires between enrollment (1993-1997) and 2022. We evaluated IBD incidence in relation to self-reported ever use of 50 pesticides among applicators and spouses. We also explored associations with intensity-weighted lifetime days (IWLD) of pesticide use among male applicators. Covariate-adjusted hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression.
RESULTS
We identified 454 IBD cases, including 227 among male applicators. In analyses with applicators and spouses combined, associations were positive (HR > 1.2) for ever vs. never use of five organochlorine insecticides, three organophosphate insecticides, one fungicide, and five herbicides. HRs were highest for dieldrin (HR = 1.59, 95%CI: 1.03, 2.44), toxaphene (HR = 1.61, 95%CI: 1.17, 2.21), parathion (HR = 1.42, 95%CI: 1.03, 1.95), and terbufos (HR = 1.53, 95%CI: 1.19, 1.96). We had limited power in many IWLD of pesticide use analyses and did not find clear evidence of exposure-response trends; however, we observed elevated HRs in all tertiles of IWLD use of terbufos compared to never use (T1 vs. never use HR = 1.52, 95%CI: 1.03, 2.24; T2 vs. never use HR = 1.53, 95%CI: 1.04, 2.26; T3 vs. never use HR = 1.51, 95%CI: 1.03, 2.23).
CONCLUSIONS
Exposure to specific pesticides was associated with elevated hazards of IBD. These findings may have public health importance given the widespread use of pesticides and the limited number of known modifiable environmental risk factors for IBD.
Topics: Humans; Male; Pesticides; Middle Aged; Female; Occupational Exposure; Inflammatory Bowel Diseases; Spouses; Adult; Aged; Farmers; Incidence; Iowa; Agriculture
PubMed: 38354883
DOI: 10.1016/j.envres.2024.118464 -
Se Pu = Chinese Journal of... Jun 2022A rapid screening method for 84 pesticide residues in dendrobium perfringens parent material with different polarities was developed using a Sin-QuEChERS Nano clean-up...
A rapid screening method for 84 pesticide residues in dendrobium perfringens parent material with different polarities was developed using a Sin-QuEChERS Nano clean-up column combined with gas chromatography-tandem mass spectrometry (GC-MS/MS). The differences in extraction efficiency of the targets were compared with different extraction solvents (acetonitrile containing 1% acetic acid, acetone) and methods (immersion with or without water). The purification effect and extraction recoveries of Sin-QuEChERS Nano method and classical dispersive solid-phase extraction (dSPE), solid-phase extraction (SPE) and QuEChERS were systematically compared using samples. The differences in matrix effects between the Sin-QuEChERS Nano method, which was more effective in purification, and the dSPE method were also analyzed. The purification effects of three commercially available Sin-QuEChERS Nano purification columns (simple matrix purification column, complex matrix purification column and herbal purification column) were compared. The applicability of the purification methods were also verified by using different parts of samples (stems, leaves and flowers). From the results, it could be concluded that weighing 2.00 g and the samples in 5 mL of water for 20 min, followed by extraction with acetonitrile containing 1% acetic acid was more effective. The average extraction recovery of the target components by Sin-QuEChERS Nano purification method was 90.5%, which further identified Sin-QuEChERS Nano-Chinese medicine purification column as the preferred purification column for dendrobium purification. The target components were separated by a DB-1701MS quartz capillary column (30 m×0.25 mm×0.25 μm) with programmed temperature rise, detected by multiple reaction monitoring (MRM) mode, and quantified by matrix-matched solution external standard method. The GC-MS/MS assay was used for the methodological validation of the 84 representative pesticides within and was carried out by GC-MS/MS detection method. The results indicated that the targets showed excellent linear correlation in different scopes with correlation coefficients () >0. 990. The limits of detection (LODs, =3) of the method were 1.5 to 5.8 μg/kg, and the limits of quantification (LOQs, =10) ranged from 5.0 to 15.0 μg/kg. The spiked recoveries of the target pesticides under different spiked levels were 68.7%-116.2%, and the relative standard deviations (RSDs, =6) were less than 15%. Compared to other typical pretreatment methods, the Sin-QuEChERS Nano method provided better performance in terms of purification. The method not only effectively removed pigments, organic acids, and alkaline interferents, but also saved preparation time. Losses due to solvent transfer were also avoided and no further vortexing or centrifugation was required, making it a simplified and effective extraction and purification procedure. The method was sensitive, rapid, simple and reliable. It effectively improved the detection efficiency during the rapid screening of pesticides in dendrobium and presented a strong practical application value. In addition, the developed method could further expand the types of target pesticides and could be used to detect more pesticide residues in foods and Chinese herbal medicine. The established Sin-QuEChERS Nano method was used for the analysis of authentic samples. The applicability of the method was evaluated by analyzing a total of 80 samples collected from Anlong, Libo, Dushan, and Yanhe County in Guizhou Province. The types of samples included dendrobium maple, (flowers, stems, leaves) and (flowers, stems, leaves, powder, tablets). At least one pesticide residue was detected in 12 samples, with a detection rate of 15%. The five pesticides with higher detection rates and residues were chlorpyrifos (0.08-0.5 mg/kg), chlorothalonil (0.06-3.2 mg/kg), propanil zinc (0.03-0.15 mg/kg), methyl parathion (0.04-0.23 mg/kg) and cyhalothrin (0.10-2.68 mg/kg). Except for the pesticides in maximum residue limits (MRLs), the pesticide residues detected from dendrobium samples were below the limits set by Chinese national standard (GB 2763-2021) and local standard DBS 52/048-2020.
Topics: Acetonitriles; Dendrobium; Gas Chromatography-Mass Spectrometry; Pesticide Residues; Pesticides; Solid Phase Extraction; Solvents; Tandem Mass Spectrometry; Water
PubMed: 35616202
DOI: 10.3724/SP.J.1123.2021.12010 -
Biotechnology Reports (Amsterdam,... Sep 2020Due to high contamination of organophosphate (OP) insecticides in agricultural products and the environment, efficient and convenient devices for their monitoring are...
Due to high contamination of organophosphate (OP) insecticides in agricultural products and the environment, efficient and convenient devices for their monitoring are necessary. Here, a simple, inexpensive, efficient, and easy-to-use absorbance-based biosensor was fabricated utilizing recombinant methyl parathion hydrolase fused with glutathione--transferase (MPH-GST), covalently immobilized onto a chitosan film-coated polystyrene microplate, for the detection of methyl parathion (MP) as a representative of OPs. Having been connected to the transducer system designed to work through an Arduino microcontroller, the biosensor could detect MP as efficiently as the conventional methods, with the detection limit of 0.1 μM, the lowest value ever reported for this method. It was stable at 25 °C for 30 days, could function 100 rounds repetitively, and yielded high recovery with real samples. Hence, this simply designed MPH-GST biosensor could be an easy and inexpensive alternative for efficient OP screening at site to help control its contamination.
PubMed: 32642456
DOI: 10.1016/j.btre.2020.e00495 -
ACS Omega Dec 2023Exfoliated kaolinite nanosheets (EXK) and their hybridization with β-cyclodextrin (β-CD/EXK) were evaluated as potential-enhanced adsorbents of methyl parathion (MP)...
Advanced Equilibrium Modeling for the Synergetic Effect of β-Cyclodextrin Integration on the Adsorption Efficiency of Methyl Parathion by β-Cyclodextrin/Exfoliated Kaolinite Nanocomposite.
Exfoliated kaolinite nanosheets (EXK) and their hybridization with β-cyclodextrin (β-CD/EXK) were evaluated as potential-enhanced adsorbents of methyl parathion (MP) in synergetic investigations to determine the effects of the different modification procedures. The adsorption behaviors were described on the basis of the energetic steric and energetic factors of the specific advanced equilibrium models (monolayer model of one energy). The functionalization process with β-CD enhanced the adsorption behaviors of MP considerably to 350.6 mg/g in comparison to EXK (291.7 mg/g) and natural kaolinite (K) (244.7 mg/g). The steric studies revealed a remarkable improvement in the quantities of the existing receptors after exfoliation ( = 134.4 mg/g) followed by β-CD hybridization ( = 162.3 mg/g) as compared to K (75.7 mg/g), which was reflected in the determined adsorption capacities of MP. Additionally, each active free site of β-CD/EXK can adsorb about 3 molecules of MP, which occur in a vertical orientation by types of multimolecular mechanisms. The energetic investigations of Gaussian energy (<8.6 kJ/mol) and adsorption energy (<40 kJ/mol) validate the physical adsorption of MP, which might involve the cooperation of dipole bonding forces, van der Waals, and hydrogen bonding. The properties and entropy values, free enthalpy, and intern energy as the investigated thermodynamic functions declared the exothermic and spontaneous behaviors of the MP adsorption.
PubMed: 38144066
DOI: 10.1021/acsomega.3c07088 -
Frontiers in Microbiology 2020is an attractive host for the directed evolution of the enzymes whose substrates cannot be transported across cell membrane. However, the generation of a mutant library...
is an attractive host for the directed evolution of the enzymes whose substrates cannot be transported across cell membrane. However, the generation of a mutant library in suffers problems of small library size, plasmid instability, and heterozygosity. Here, a large library of random mutant was created by inserting error-prone PCR (epPCR) products to the chromosome of . Specifically, the epPCR product was fused with flanking regions and antibiotic resistant marker using a PCR-based multimerization method, generating insertion construct. The epPCR product was integrated into the chromosome via homologous recombination after the insertion construct was transformed into the supercompetent cells of strain SCK6. The transformation efficiency of the insertion construct was improved through co-expressing homologous recombination-promoting protein NgAgo, raising the number of competent cells, and increasing the length of flanking regions. A library containing 5.31 × 10 random mutants was constructed using per μg insertion construct, which is sufficient for directed evolution. The library generation process was accomplished within 1 day. The effectiveness of this method was confirmed by improving the activity of Methyl Parathion Hydrolase (MPH) toward chlorpyrifos and by enhancing the secretion level of MPH in . Taken together, the present work provides a fast and efficient method to integrate epPCR products into the chromosome of , facilitating directed evolution and expression optimization of target proteins.
PubMed: 33281764
DOI: 10.3389/fmicb.2020.570280 -
Foods (Basel, Switzerland) Aug 2023In this study, a colorimetric sensor was developed for the detection of organophosphorus pesticides (OPs) using a heterogeneous nanozyme with phosphatase-like activity....
In this study, a colorimetric sensor was developed for the detection of organophosphorus pesticides (OPs) using a heterogeneous nanozyme with phosphatase-like activity. Herein, this heterogeneous nanozyme (Au-pCeO) was obtained by the modification of gold nanoparticles on porous cerium oxide nanorods, resulting in synergistic hydrolysis performance for OPs. Taking methyl parathion (MP) as the target pesticide, the catalytic performance and mechanism of Au-pCeO were investigated. Based on the phosphatase-like Au-pCeO, a dual-mode colorimetric sensor for MP was put forward by the analysis of the hydrolysis product via a UV-visible spectrophotometer and a smartphone. Under optimum conditions, this dual-mode strategy can be used for the on-site analysis of MP with concentrations of 5 to 200 μM. Additionally, it can be applied for MP detection in pear and lettuce samples with recoveries ranging from 85.27% to 115.87% and relative standard deviations (RSDs) not exceeding 6.20%, which can provide a simple and convenient method for OP detection in agricultural products.
PubMed: 37569249
DOI: 10.3390/foods12152980 -
Journal of Pharmaceutical Analysis Apr 2021A highly sensitive and selective method was developed for both UV-vis spectrophotometric and fluorimetric determination of organophosphorus pesticides (OPs). This method...
A highly sensitive and selective method was developed for both UV-vis spectrophotometric and fluorimetric determination of organophosphorus pesticides (OPs). This method used silver nanoparticles (AgNPs) modified with graphitic carbon nitride (g-CN). The AgNPs reduced the fluorescence intensity of g-CN. Acetylthiocholine (ATCh) could be catalytically hydrolyzed by acetylcholinesterase (AChE) to form thiocholine, which induces aggregation of the AgNPs. This aggregation led to the recovery of the blue fluorescence of g-CN, with excitation/emission peaks at 310/460 nm. This fluorescence intensity could be reduced again in the presence of OPs because of the inhibitory effect of OPs on the activity of AChE. The degree of reduction was found to be proportional to the concentration of OPs, and the limit of fluorometric detection was 0.0324 μg/L (S/N = 3). In addition, the absorption of the g-CN/AgNPs at 390 nm decreased because of the aggregation of the AgNPs, but was recovered in presence of OPs because of the inhibition of enzyme activity by OPs. This method was successfully applied to the analysis of parathion-methyl in real samples.
PubMed: 34012694
DOI: 10.1016/j.jpha.2020.04.007 -
Molecules (Basel, Switzerland) Nov 2023An unprecedented photocatalyst, SmEuSbO, was successfully fabricated in this paper, through a high-temperature solid-state calcination method, which represented its...
An unprecedented photocatalyst, SmEuSbO, was successfully fabricated in this paper, through a high-temperature solid-state calcination method, which represented its first ever synthesis. Additionally, using the solvothermal method, the SmEuSbO/ZnBiSbO heterojunction photocatalyst (SZHP) was fabricated, marking its debut in this study. XRD analysis confirmed that both SmEuSbO and ZnBiSbO exhibited pyrochlore-type crystal structures with a cubic lattice, belonging to the Fd3m space group. The crystal cell parameter was determined to be 10.5682 Å or 10.2943 Å for SmEuSbO or ZnBiSbO, respectively. The band gap width measured for SmEuSbO or ZnBiSbO was 2.73 eV or 2.61 eV, respectively. Under visible light irradiation for 150 min (VLTI-150 min), SZHP exhibited remarkable photocatalytic activity, achieving 100% removal of parathion methyl (PM) concentration and 99.45% removal of total organic carbon (TOC) concentration. The kinetic constant () for PM degradation and visible light illumination treatment was determined to be 0.0206 min, with a similar constant of 0.0202 min observed for TOC degradation. Remarkably, SZHP exhibited superior PM removal rates compared with SmEuSbO, ZnBiSbO, or N-doped TiO photocatalyst, accompanied by removal rates 1.09 times, 1.20 times, or 2.38 times higher, respectively. Furthermore, the study investigated the oxidizing capability of free radicals through the use of trapping agents. The results showed that hydroxyl radicals had the strongest oxidative capability, followed by superoxide anions and holes. These findings provide a solid scientific foundation for future research and development of efficient heterojunction compound catalysts.
PubMed: 38067453
DOI: 10.3390/molecules28237722 -
ACS Measurement Science Au Jun 2023The development and increase in the number of crops recently have led to the requirement for greater efficiency in world food production and greater consumption of...
The development and increase in the number of crops recently have led to the requirement for greater efficiency in world food production and greater consumption of pesticides. In this context, the widespread use of pesticides has affected the decrease in the population of pollinating insects and has caused food contamination. Therefore, simple, low-cost, and quick analytical methods can be interesting alternatives for checking the quality of foods such as honey. In this work, we propose a new additively manufactured (3D-printed) device inspired by a honeycomb cell, with 6 working electrodes for the direct electrochemical analysis of methyl parathion by reduction process monitoring in food and environmental samples. Under optimized parameters, the proposed sensor presented a linear range between 0.85 and 19.6 μmol L, with a limit of detection of 0.20 μmol L. The sensors were successfully applied in honey and tap water samples by using the standard addition method. The proposed honeycomb cell made of polylactic acid and commercial conductive filament is easy to construct, and there is no need for chemical treatments to be used. These devices based on 6 working electrodes array are versatile platforms for rapid, highly repeatable analysis in food and environment, capable of performing detection in low concentrations.
PubMed: 37360039
DOI: 10.1021/acsmeasuresciau.3c00003