绿色农药
绿色农药

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  • [资讯] Fluorescence assay for three organophosphorus pesticides in agricultural products based on Magnetic-Assisted fluorescence labeling aptamer probe
    摘要:There has been increasing recent concern about the agricultural use of organophosphorus pesticides. A rapid and sensitive fluorescence assay for the detection of three organophosphorus pesticides has therefore been developed using 6carboxyfluorescein labeling aptamer as the probe and functionalized magnetic nanoparticles as the separation carrier. The aptamer hybridized with complementary DNA conjugated on the surface of the magnetic nanoparticles to form a magnetic aptamercomplementary DNA complex. Upon introducing the target organophosphorus pesticide, the aptamer departed from the complementary DNA, resulting in the fluorescence signal. Under optimized conditions, the limits of detection (LODs, SN 3) for trichlorfon, glyphosate, and malathion were 72.20 ng L1, 88.80 ng L1, and 195.37 ng L1, respectively. The method was applied for the detection of trichlorfon, glyphosate, and malathion in spiked lettuce and carrot samples. The recoveries were in the range of 79.4%118.7%, which were in good agreement with those obtained by gas chromatography, and the relative standard deviations were also acceptable. The method therefore has high sensitivity, so provides a means for the detection of multiple organophosphorus pesticides.
  • [资讯] A label-free electrochemical aptasensor based on 3D porous CS/rGO/GCE for acetamiprid residue detection
    摘要:A novel label-free electrochemical aptasensor was fabricated based on a three-dimensional porous electrode (3D-CS/rGO/GCE) for the detection of acetamiprid residues. The sensing signal was generated by the DNA itself. The porous electrode was prepared by electrodeposition in situ and characterized by scanning electron microscope (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). These results indicated that the porous electrode has a uniform nanoporous structure, high active area, and excellent conductivity, leading to improve the transmission efficiency of current signals. The 3D-CS/rGO/GCE was used to increase a load of acetamiprid aptamer on the electrode. Meanwhile, DNA self-assembly strategy was used to further increase the DNA amounts. Thus the electrochemical current was amplified significantly due to increased phosphate group amounts by the above synergistic effect. The determination of acetamiprid residues using square wave voltammetry (SWV) showed good sensitivity, with the linear range from 0.1 pM to 0.1 mu M and the detection limit was 71.2 fM. The label-free electrochemical aptasensor was also used to detect acetamiprid residues in tea samples with satisfactory results.
  • [资讯] Attenuation of nitrates, antibiotics and pesticides from groundwater using immobilised microalgae-based systems
    摘要:Groundwater pollution by nitrates and organic microcontaminants (OMCs) such as pesticides and antibiotics has increased in recent years due to the intensification of agriculture and livestock activities. Here we demonstrate, for the first time, the suitability of using microalgae immobilised in different materials (luffa sponge and polyurethane foam) to attenuate nitrates, antibiotics (sulfacetamide, sulfamethazine, and sulfamethoxazole), pesticides (bromacil, atrazine, diuron, bentazone, and mecoprop) from groundwater in two operational modes (batch and continuousfeeding). The results from the batch experiments show that OMC kinetic removal rates ranged from 0.01 to 0.18 d 1 , with halflives from 4 to 69 days. Immobilised microalgae in luffa and foam materials in the batch study was found to enhance the attenuation of selected OMCs from 36% to 51%, on average, after 10 operational days. Microalgae reactors in continuousfeeding operational mode out performed batch mode in terms of OMC removal (65% vs. 50%, on average) at a hydraulic residence time (HRT) of 8 days, whereas nitrate removal was greater in the batch experiments (81 vs. 48%, on average). OMC attenuation showed a high HRT dependence, but immobilised reactors were more resilient to the decrease in HRT. Further studies are needed, including the assessment of transformation products as well as the scaleup of the system to check the feasibility of the technology. Nevertheless, we expect our assay to be the starting point for the applicability of immobilisedmicroalgaebased systems for the treatment of polluted groundwater.
  • [资讯] A novel fluorescent recombinant cell-based biosensor for screening NLRP3 inflammasome inhibitors
    摘要:Nucleotide-binding oligomerization domain-like receptor pyrin-domain-containing protein 3 (NLRP3) inflammasomes trigger a defense mechanism in response to physiological or pathological reactions caused by various injuries, and they have critical roles in the development of many major diseases. The development of plant source anti-inflammatory agents and the assessment of their anti-inflammatory properties still face many challenges, such as high costs and long testing periods. Exogenous anti-inflammatory factors can be evaluated at the protein level using the NLRP3-green fluorescent protein (GFP) THP-1 cell-based biosensor. To achieve this, THP-1 cells were stably transfected with a plasmid encoding the GFP reporter gene that is under the transcriptional regulation of the NLRP3 promoter. Because the NLRP3 promoter controls the green fluorescent signal, the fluorescence is an indicator of NLRP3 activity. Our results show the fluorescence intensity was dependent on both the degree of inflammation and the effect of the anti-inflammatory agent. Here, we successfully used the biosensor to screen an NLRP3 inhibitor in the presence of polyphenols. Our results demonstrate the potential of this cell-based biosensor in monitoring the development of inflammation and in screening inflammatory inhibitors.
  • [资讯] Ratiometric ATP detection on gliding microtubules based on bioorthogonal fluorescence conjugation
    摘要:An ingenious microtubule functionalization strategy based on the novel bioorthogonal conjugation is developed to construct fluorescent ratiometric probes for ATP sensing. By single excitation, newly synthesized probe RT-1 exhibited green emission (485 nm) from the bioorthogonal fluorescence conjugation part and orange emission (584 nm) from the ATP sensing part. The fluorescence intensity ratio (I-584/I-485) displayed good linear response in ATP ranges of 0-2.5 mM (y = 0.9282x + 0.2398, R-2 = 0.9705, LOD = 0.0354 mM) and 2.0-10.0 mM (y = 2.7153x-3.6234, R-2 = 0.9911, LOD = 0.0121 mM). Moreover, a paclitaxel derivate probe RT-2 was developed to functionalize in vitro polymerized microtubule for in situ ATP detection. This simple and convenient strategy is anticipated to stimulate more microtubule related applications in both in vitro and intracellular studies.
  • [资讯] A portable device enabling fluorescent-to-electric resistant transduction for selective Cr3+ detection based on its slow ligand bind kinetics
    摘要:Using simple and commonly available devices for signal reading has attracted much attention recently for DNA-based sensors. Most previous works focused on electrochemical or colorimetric signals. In this work, a portable device was structured by simple electronic and 3D-printed components to convert fluorescence signal to electric resistance with reading by a multimeter. To demonstrate its application, we took advantage of the slow ligand bind kinetics of Cr3+ to promote DNA adsorption on metal oxide nanoparticles (MONPs). Nanoceria (CeO2), screened from a total of 13 kinds of MONPs, possesses high specificity for Cr3+ from other metal ions. EDTA can mask other metal ions, while it cannot bind Cr3+ quickly so that Cr3+ promotes DNA adsorption and thus fluorescence quenching. The linear range is from 0 to 2 mu M Cr3+ with a LOD of 0.02 mu M. Using common electronic components and the 3D-printed miniaturized device, the sensor to transfer fluorescence to electric resistant signal was also measured by a digital multimeter. In this case, the LOD is about 1 mu M Cr3+. Such a strategy may provide a simple and general approach for fluorescent portable device fabrication and may find applications for other onsite sensing applications.
  • [资讯] Targeting tumor-intrinsic hexosamine biosynthesis sensitizes pancreatic cancer to anti-PD1 therapy
    摘要:Pancreatic ductal adenocarcinoma (PDAC) is considered to be a highly immunosuppressive and heterogenous neoplasm. Despite improved knowledge regarding the genetic background of the tumor and better understanding of the tumor microenvironment, immune checkpoint inhibitor therapy (targeting CTLA4, PD1, PDL1) has not been very successful against PDAC. The robust desmoplastic stroma, along with an extensive extracellular matrix (ECM) that is rich in hyaluronan, plays an integral role in this immune evasion. Hexosamine biosynthesis pathway (HBP), a shunt pathway of glycolysis, is a metabolic node in cancer cells that can promote survival pathways on the one hand and influence the hyaluronan synthesis in the ECM on the other. The rate-limiting enzyme of the pathway, glutamine-fructose amidotransferase 1 (GFAT1), uses glutamine and fructose 6-phosphate to eventually synthesize uridine diphosphate N-acetylglucosamine (UDP-GlcNAc). In the current manuscript, we targeted this glutamine-utilizing enzyme by a small molecule glutamine analog (6-diazo-5-oxo-L-norleucine [DON]). Our results showed that DON decreased the self-renewal potential and metastatic ability of tumor cells. Further, treatment with DON decreased hyaluronan and collagen in the tumor microenvironment, leading to an extensive remodeling of the ECM and an increased infiltration of CD8+ T cells. Additionally, treatment with DON sensitized pancreatic tumors to anti-PD1 therapy, resulting in tumor regression and prolonged survival.
  • [资讯] Use of novel film forming starch complexes to directly and indirectly reduce insect damage to plants
    摘要:Filmforming polymer technologies can contribute to insectpest control by causing adverse effects directly to insects such as slowing development, causing mortality, andor indirectly as a spray ingredient that improves pesticide efficacy by resisting environmental degradation such as washoff by rain. Amylose complexes produced from either fatty acid amylose sodium palmitate (NaPalm) or fatty ammonium salts amylosehexadecylammonium chloride complex (HexAm), when blended with polyvinyl alcohol (PVOH), dry to form films that were significantly more water resistant then films formed by their constitutive components and adhered strongly to treated soybean Glycine max (L.) Merrill leaves with no impact on photosynthesis or yield in simulated field trials. As an experimental bioinsecticide formulation to resist washoff, AfMNPV baculovirus was incorporated into both amylose complex formulations and sprayed on soybean. After a simulated rain event, soybean treated with the baculovirusNaPalmPVOH (1:1) retained 93% of the original insecticidal activity against Trichoplusia ni (Hbner) larvae as compared with the baculovirus only treatment, 53% activity retained. Curiously, initial insecticidal efficacy of filmforming treatments was significantly lower against T. ni when compared with unformulated baculovirus treatments, thus prompting further investigations. Both amylose complexes reduced larval feeding when sprayed on soybean, corresponding with reduced insect mortality by the baculovirus, which must be ingested to initiate infection. HexAm film coating over artificial diet inhibited the growth and development of T. ni and caused increased T. ni mortality and developmental delay as film thickness of HexAmPVOH increased. These investigations demonstrate the potential of a new modified starch complex formulation to serve as a protective film forming agent and contribute to control of insect pests.
  • [资讯] Disinfection by-product formation during UV/Chlorine treatment of pesticides in a novel UV-LED reactor at 285 nm and the mitigation impact of GAC treatment
    摘要:The UVChlorine process has gained attention in recent years due to the high quantum yield and absorbance of the chlorine species. However, there are still many unknowns around its application as a treatment for drinking water. The potential for the formation of disinfection byproducts (DBPs) is one of them. There are no studies reporting on the formation of trihalomethanes (THMs) or haloacetic acids (HAAs) in complex matrices, such as real source waters, at UV wavelengths tailored to the UVChlorine process, which has been possible thanks to the development of light emitting diodes (LEDs). In addition, consideration of mitigation measures that might be needed after UVChlorine treatment for full scale application have not been previously reported. Specifically, the novelty of this work resides in the use of an innovative reactor using UVLEDs emitting at 285 nm for the removal of three pesticides (metaldehyde, carbetamide and mecoprop), the evaluation of THM, HAA and bromate formation in real water sources by UVChlorine treatment and the mitigation effect of subsequent GAC treatment. A new parameter, the applied optical dose (AOD), has been defined for UV reactors, such as the one in the present study, where the irradiated volume is nonuniform. The results showed the feasibility of using the UVChlorine process with LEDs, although a compromise is needed between pH and chlorine concentration to remove pesticides while minimising DBP formation. Overall, the UVChlorine process did not significantly increase THM or HAA formation at pH 7.98.2 at the studied wavelength. At acidic pH, however, THM formation potential increased up to 30% after UVChlorine treatment with concentrations up to 60 gL. HAA formation potential increased between 100 and 180%, although concentrations never exceeded 35 gL. In all cases, GAC treatment mitigated DBP formation, reducing THM formation potential to concentrations between 3 and 16 gL, and HAA formation potential between 4 and 30 gL.
  • [资讯] Development of a molecularly imprinted polymer electrochemical sensor and its application for sensitive detection and determination of malathion in olive fruits and oils
    摘要:Malathion (MAL) is an organophosphorus (OP) insecticide. It is a cholinesterase inhibitor, which can pose serious health and environmental problems. In this study, a sensitive and selective molecular imprinted polymer (MIP) based on screenprinted gold electrodes (AuSPE) for MAL detection in olive oils and fruits, was devised. The MIP sensor was prepared using acrylamide as the functional monomer and MAL as the template. Subsequently, the morphology of the electrode surface was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electrochemical characterization of the developed MIP sensor was performed by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) techniques. The operational repeatability and stability of the sensor were studied. It was found to have a dynamic concentration range of (0.1 pg mL 1 1000 pg mL 1 ) and a low limit of detection (LOD) of 0.06 pg mL 1 . Furthermore, the sensor was employed to determine MAL content in olive oil with a recovery rate of 87.9% and a relative standard deviation of 8%. It was successfully applied for MAL determination in real samples and promise to open new opportunities for the detection of OP pesticides residues in various food products, as well as in environmental applications.
  • [资讯] Development, validation, comparison, and implementation of a highly efficient and effective method using magnetic solid-phase extraction with hydrophilic-lipophilic-balanced materials for LC-MS/MS analysis of pesticides in seawater
    摘要:To achieve multipesticides residue analysis in seawater, hydrophiliclipophilicbalanced magnetic particles were designed and fabricated by swelling polymerization of divinyl benzene (DVB) and Nvinyl pyrrolidone (NVP) on the surface of Fe 3 O 4 @SiO 2 magnetic particles. The ratio of DVB to NVP was adjusted to achieve a proper balance in hydrophilicity and lipophilicity. The obtained magnetic particles were systematically characterized by TEM, SEM, FTIR and vibrating sample magnetization. Based on the optimized magnetic nanoparticles, a sensitive magnetic solidphase extraction method was developed for the simultaneous preconcentration and determination of 96pesticide residues from largevolume seawater samples prior to being detected by liquid chromatographytandem mass spectrometry. Recoveries of pesticides in spiked seawater samples (0.001, 0.01, 0.1, 1.0 g L 1 ) ranged from 62% to 112% with RSDs less than 21%. The method limits of detection of 96 pesticides ranged from 0.13 to 0.42 ng L 1 , the method limits of quantification of 96 pesticides ranged from 1.0 to 10 ng L 1 . The method was successfully applied to pesticide residue analysis in water samples from Jiulong River Estuary of China, demonstrating the prospects of this technique as a potential method for the rapid determination of trace levels of multipesticide residues in seawater.
  • [资讯] Concentration, distribution and sources of perfluoroalkyl substances and organochlorine pesticides in surface sediments of the northern Bering Sea, Chukchi Sea and adjacent Arctic Ocean
    摘要:Perfluoroalkyl substances (PFAS) and organochlorine pesticides (OCPs) in surface sediments were investigated from the Bering Sea, the Chukchi Sea and adjacent Arctic Ocean in 2010. Total concentrations (dry weight) of Sigma(14)PFAS in surface sediments (0.85 0.22 ng g(1)) of the Bering Sea were lower than that in the Chukchi Sea and adjacent Arctic Ocean (1.27 0.53 ng g(1)). Perfluorobutanoic acid (PFBS) and perfluorooctanoic acid (PFOA) were the dominant PFAS in these areas. The concentrations of Sigma(15)OCPs in the sediment of the Bering Sea (13.00 6.17 ng g(1)) was slightly higher than that in the Chukchi and Arctic Ocean (12.05 2.27 ng g(1)). The most abundant OCPs were hexachlorocyclohexane isomers (HCHs) and dichlorodiphenyltrichloroethane (DDT) and its metabolites. The composition patterns of HCHs and DDTs indicated that they were mainly derived from the early residues via river runoff. Increasing trends of PFAS, HCHs and DDTs in surface sediments from the Bering Sea to the Arctic Ocean were found, indicating oceanic transport. In summary, the concentrations of OCPs were orders of magnitude greater than the observed PFAS concentrations, and the concentrations of PFAS and OCPs in surface sediments from the Bering Sea to the Chukchi Sea and adjacent Arctic Ocean are at the low to moderate levels by comparing with other coastal and marine sediments worldwide. (C) 2019 Elsevier Ltd. All rights reserved.
  • [资讯] Seasonal, Spatial Variation, and Potential Sources of Organochlorine Pesticides in Water and Sediment in the Lower Reaches of the Dong Nai River System in Vietnam
    摘要:The goals of the current study were (1) to examine seasonal and spatial variation of selected OCPs concentrations and (2) to identify potential sources of the pollutants in the lower reaches of the Dong Nai River system. Fortyeight water and sediment samples were taken from 12 stations in the dry and rainy seasons to determine the concentrations of dichlorodiphenyltrichloroethane and its metabolites (total DDTs), hexachlorocyclohexane isomers (total HCHs), heptachlor, aldrin, dieldrin, and endrin. The concentrations of total DDTs (0.30), total HCHs (0.29), Aldrin (0.068), heptachlor (0.04, mu g L1) in water, and total DDTs (8.04), total HCHs (4.51), and Aldrin (1.52, mu g kg(1)) in sediment were significantly higher in the rainy season than in the dry season (0.14, 0.12, 0.008, 0.009 in water and 3.49, 2.29, and 0.4 in sediment, respectively). Cluster analysis grouped 12 sampling stations into 2 groups, of which group 1 (3 stations) had higher concentrations of total DDTs, total HCHs, Aldrin, heptachlor, and dieldrin in both water and sediment than in group 2. Compositional analysis of total DDTs revealed that DDT residue could be decomposed significantly for the past years and that anaerobic decomposition could be predominant. Principal component analysisfactor analysis (PCAFA) indicated that the potential sources of OCPs in the study stations could come from residential and agricultural areas located in the upper catchment or areas surrounding the studied stations. In short, OCPs concentration in the studies area could depend on seasonal, spatial variation, and transport of OCPs from upper parts or surrounding areas.
  • [资讯] Characterization of colloid-size copper-based pesticide and its potential ecological implications
    摘要:The intensive use of Cubased pesticides in agriculture could have an unintended impact on the ecosystems and human health via different exposure pathways. This paper presents the results of experiments involving colloidal stability, aggregation, and dissolution of Cu2O commercial pesticide under various environmental conditions in view of ecological implications. The investigated pesticide contains 750gkg1 Cu (75% weight of product), Cu2O particles with sizes1m, and nominal size fraction of Cu2O nanoparticles. The copresence of Ca2 (20mM) and humic acid (HA, 15mgL1) significantly modulates (p0.001) the colloidal stability and mobility of particles. The dissolution of Cu at pH 5.5 was about 85%, 90%, and 75% weight more than the dissolution of Cu at pH 7.0, pH 8.5, and pH 7.0 and pH 8.5 combined, respectively in all dispersions. However, increasing HA content from 0 to 15mgL1 reduced the dissolution of Cu by 56%, 50%, and 40% weight at pH 5.5, 7.0, and 8.5, respectively. Thus, pH below 7.0 is a critical factor to control the dissolution and bioavailability of Cu that may pose ecotoxicity and environmental pollution, whereas pH above 7.0 and the presence of HA attenuate the pH effect. These findings provide insight into how the potential mobility and bioavailability of Cu is modulated by the water chemistry under various environmental scenarios and media.
  • [资讯] Preparation and Characterization of a Novel Waterborne Lambda-Cyhalothrin/Alkyd Nanoemulsion.
    摘要:Inefficient usage and overdosage of conventional pesticide formulations has resulted in large economic losses and environmental pollution due to their poor water solubility and weak adhesion to foliage. In order to develop a green and efficient pesticide formulation, a kind of alkyd resin (AR) based on vegetable oil was first synthesized and used to fabricate the lambdacyhalothrinAR (LCAR) nanoemulsion via in situ phase inverse emulsification, and its properties were then investigated. Results showed that the particle size of the LCAR nanoemulsion was 50150 nm with maximum LC loading capacity of as much as 40.9 wt %, high encapsulation efficiency 90%, and great stability in multiple environments. The LCAR nanoemulsion exhibited better controlled release characteristics compared with LC commercial formulations, and a stronger adhesion on the foliage of the resulted nanoemulsion was also observed, which was attributed to low surface tension and strong interactions with foliar surfaces.
  • [资讯] Insecticide Risk in US Surface Waters: Drivers and Spatiotemporal Modeling
    摘要:Although pesticide contamination in agricultural surface waters is a common phenomenon, largescale studies dealing with the responsible drivers are rare. We used data from 259 publications reporting 5830 individual water or sediment concentrations of 32 insecticides and their metabolites in 644 US surface waters to determine the factors driving insecticide risks, that is, exceedance of regulatory threshold levels (RTLs). Multiple linear regressions (R2 adj. 49.676.5) revealed that toxicitynormalized agricultural insecticide use (i.e. use divided by toxicity) was the most important driver. Burst rainfall erosivity and irrigation practices also had riskpromoting effects, whereas time, catchment size, and sampling interval had riskdemoting effects. A regression model (R2 adj. 62.2, n 1833) for small, medium, and large running waters was validated and used for risk mapping at the national scale, highlighting multiple regions, where the comparison of predicted insecticide concentrations with their RTLs indicate adverse conditions for aquatic organisms. Particularly in smaller streams, risks were most pronounced with an average RTL exceedance frequency of 27.7% in all grid cells (n 9968). Finally, mixture toxicity was mainly (about 76.7%) explained by the most toxic compound in the mixture, causing 95.7% of RTL exceedances. Identifying the factors, which drive exposure for all relevant insecticide classes, and subsequently mapping these risks for surface waters of various sizes across the U.S., will support future risk management.
  • [资讯] How many premature deaths from pesticide suicide have occurred since the agricultural Green Revolution?
    摘要:Introduction: The agricultural Green Revolution in the 1950s and 60s is thought to have averted many deaths from famine. However, it also introduced highly hazardous pesticides such as parathion and endrin into poor rural communities that were totally unequipped to store or use them safely. Pesticide selfpoisoning rapidly became one of the two most common global means of suicide. Thus far, no attempt has been made to enumerate the total number of deaths that have occurred subsequent to the Green Revolution. Objective: To calculate plausible estimates for the total global number of pesticide suicides that have occurred since 1960. Methods: We performed a literature review on Medline and Embase databases to July 2019 to find papers that reported national or global numbers of pesticide suicides. We restricted our search to papers published in English. We used the search terms: pesticide) OR insecticide) OR paraquat) OR organophosphate) OR organophosphorus) OR agrochemical) AND suicide) OR ) OR deliberate) AND poison in all fields. These searches identified 2,144 papers a further 8 citations were added through the searching of reference lists and our own paper collections. 2,136 papers were excluded as they contained no data on pesticide suicide, or were case reports, case series, or related to specific sociodemographic groups, or were nonhuman studies. This left 16 papers giving country specific or global pesticide suicide data. Longterm national trend in pesticide suicides: We found studies from one low and middleincome country (Sri Lanka) that recorded longterm trends in suicide throughout the Green Revolution. These data showed a steady increase in suicides from 1960 to the early 1970s, with a more rapid increase from 1979 to 1984. The number of suicides plateaued until 1995, when they started a steady almost linear decrease that has continued at least until 2015. We used the Sri Lankan epidemiology as a model of the incidence of pesticide suicides in other low and middleincome countries. Data from Bangladesh suggested that the decrease might have started in 2002. Estimating global numbers since 1960: Starting from a conservative estimate of zero deaths in 1960, the best estimate of the total global burden of pesticide suicides from 1960 to 2018 is 14,272,105 or 14,936,000 (depending on whether a fall in incidence began in 1995 or 2002), with a plausible range of 9,859,667 to 17,303,333 deaths. These are likely underestimates because suicide is illegal in many countries, and most pesticide suicides occur in poor rural areas without effective death registration systems. Conclusions: Pesticide selfpoisoning has been a major clinical and public health problem in rural Asia for decades, while being long ignored. Most pesticide suicides are relatively impulsive with little planning: in the absence of highly hazardous pesticides, many people would have survived their suicidal impulse, gone on to find support amongst family, community, and health services, and lived a full life. Pesticide suicides must therefore be considered a category 4 occupation condition following Schillings classification if they had not been brought into rural communities for agricultural use, pesticide suicides would not have occurred. Preventing these deaths should be a global public health priority.
  • [资讯] Amphiphilic Polymer-Mediated Aggregation-Induced Emission Nanoparticles for Highly Sensitive Organophosphorus Pesticide Biosensing
    摘要:Biosensing applications require signal reporters to be sufficiently stable and biosafe as well as highly efficient. Aggregationinduced emission (AIE) nanoparticles have proven to be capable of cellimaging and cancer therapy however, realizing sensitive detection of biomolecules remains a great challenge because of their instability, biotoxicity, and lack of modifiable functional groups. Herein, we report a selfassembling strategy to fabricate AIE nanoparticles (PTDNPs) through the dispersion of amphiphilic polymers (PTDs) in phosphatebuffered saline. The PTDs were prepared through radical copolymerization of N(1,2,2triphenylvinyl)4acetylaniline and dimethyl diallyl ammonium chloride. We found that the particle size, morphology, functional groups, and fluorescence property of PTDNPs can be finetuned. Further, PTDNPs0.10 were chosen as signal reporters to detect organophosphorus pesticides (OPs) with the aid of gold nanoparticles. Their sensing performance on OPs is superior to that using Cdotquantum dotrhodamine B as the signal reporter. This study not only provides new possibilities to fabricate novel AIE nanoparticles with exceptional properties, but also facilitates the AIE nanoparticles application for target analyte biosensing.
  • [资讯] Temporal variability in urinary pesticide concentrations in repeated-spot and first-morning-void samples and its association with oxidative stress in healthy individuals
    摘要:Exposure of humans to pesticides is widespread. Measurement of urinary levels of pesticides and their metabolites is often used in the assessment of body burdens and exposure doses to these chemicals. An understanding of temporal variability in urinary levels of pesticides within individuals is critical for accurate exposure assessment. We examined within and betweenindividual variability in concentrations of nine organophosphate and pyrethroid insecticides as well as two phenoxy herbicides in urine collected consecutively for up to 44 days from 19 individuals. Seven oxidative stress biomarkers also were measured in urine samples to elucidate their relationship with pesticide exposure. Intraclass correlation coefficients (ICCs) were calculated to assess reproducibility in urinary pesticide concentrations from repeated measures. Sensitivity and specificity analyses were performed to evaluate the suitability of spot urine to characterize average exposures. Data analysis was further limited to seven pesticides and their metabolites, which had a detection frequency of 60%. Poor reproducibility was found for the seven pesticides and their metabolites in both spot (ICCs 0.24) and firstmorningvoid (FMV) samples (ICCs 0.38) collected during the 44day study period. Use of singlespot or FMV sample to classify high (top 33%) concentrations showed high specificities (0.730.85) but low sensitivities (0.450.70). The minimum number of samples (k) required per individual to estimate participantspecific mean value for pesticides (within 20% of the “true” values) were 28140 and 18119 for spot and FMV samples, respectively. Repeated longitudinal measurements of these pesticides and their metabolites in urine showed considerable withinindividual variability in both spot and FMV samples. Urinary concentrations of seven pesticides and their metabolites were significantly correlated with oxidative damage to lipids, proteins, and DNA.
  • [资讯] Amphiphilic Polymer-Mediated Aggregation Induced Emission Nanoparticles for Highly Sensitive Organophosphorus Pesticide Biosensing
    摘要:Biosensing applications require signal reporters to be sufficiently stable and biosafe, as well as highly efficient. Aggregation induced emission (AIE) nanoparticles have proven to be capable of cell imaging and cancer therapy, however, realizing biomolecules sensitive detection remains great challenges because of their instability, biotoxicity and lack of modifiable functional groups. Herein, we report a selfassembling strategy to fabricate AIE nanoparticles (PTDNPs) through dispersion of amphiphilic polymers (PTD) in phosphate buffer saline (PBS). The PTD were prepared through radical copolymerization of N(1,2,2triphenylvinyl)4acetylaniline (TPENA) and dimethyl diallyl ammonium chloride (DMDAAC). We found that the particle size, morphology, functional groups and fluorescence property of PTDNPs can be finetuned. Further, PTDNPs0.10 were chosen as signal reporters to detect organophosphorus pesticides (OPs) with the aid of gold nanoparticles (AuNPs). Their sensing performance on OPs is superior to that using Cdotquantum dot rhodamine B as signal reporter. This study not only provides new possibilities to fabricate novel AIE nanoparticles with exceptional properties, but also facilitates the AIE nanoparticles application for target analytes biosensing.

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