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The samples of greenhouse cucumbers were collected from the Central Fruit and Vegetable Market of Tabriz between June and December 2017. In the twenty-four cucumber samples (unwashed, washed, peeled), the residue of 18 organophosphates pesticides (OPPs) was analyzed using gas chromatography-mass spectrometry (GC-MS) following the modified QuEChERS method (quick, easy, cheap, effective, rugged and safe). Chronic non-carcinogenic risk assessment from pesticide residues in the samples was also performed for age groups of adults (women and men) and children using the Monte Carlo Simulation (MCS). Amongst the eighteen studied pesticides, eight pesticides including dimethoate, diazinon, methyl parathion, fenitrothion, chlorpyrifos, profenofos, ethion, and azinphos-methyl were detected. Pesticide residues were detected in 100% of unwashed, washed and peeled samples in the range of 0.08 to 0.37 mg.kg-1, 0.03 to 0.17 mg.kg-1 and 0.01 to 0.08 mg.kg-1, respectively. The maximum and minimum values were found for diazinon pesticides with 0.37 mg.kg-1 and profenofos and fenitrothion with 0.01 mg.kg-1. 100 % of samples contained at least three pesticide residues (dimethoate, diazinon, and methyl parathion), while 87.5% of the samples contained more pesticides residues. The residues of dimethoate, diazinon, and methyl parathion were above Maximum Residue Limits (MRL) in 100%, 83.33%, and 66.66% of samples, respectively. The identified residues were more than the EU MRLs and the IR MRLs in 100% and 95.83% samples, respectively. The mean reduction of pesticide residues in the washed and peeled samples was in the range of 37.74 to 56.52% and 66.66 to 92.30%, respectively. According to the performed risk assessment, there is no significant non-carcinogenic health risk due to the consumption of cucumber for the age group of adults. Hence, there is a considerable non-carcinogenic health risk to children due to the consumption of unwashed (HI = 2.22) and water-washed (HI = 1.36) greenhouse cucumbers. [ABSTRACT FROM AUTHOR]

Herein, a deep eutectic solvent (DES)‐based miniaturized pressurized liquid extraction in combination with DES‐based dispersive liquid–liquid microextraction (DLLME) was developed for the extraction of organophosphorus pesticides (parathion–methyl, triazophos, parathion, diazinon, and phoxim) from egg powder samples prior to their analysis by a high‐performance liquid chromatography‐diode array detector. In this work, first, the analytes' extraction was done by a pressurized liquid phase extraction for effective extraction of the analytes from the solid matrix, and then they were concentrated on a DLLME for more concentration of the analytes to reach low limits of detections. The use of DESs was done in both steps to omit the use of toxic organic solvents. Satisfactory results including high extraction recoveries (74–90%), great repeatability (relative standard deviations equal or less than 4.3% and 5.3% for intra‐ and inter‐day precisions), and low limits of detection (0.11–0.29 ng/g) and quantification (0.38–0.98 ng/g) were attained under the optimum conditions. Lastly, the suggested approach was utilized for the determination of the studied pesticides in various egg powder samples marketed in Tabriz, Iran. [ABSTRACT FROM AUTHOR]

Background: The pesticides are potentially toxic compounds that have become omnipresent in the environment. These toxicants modulate and/or disrupt the reproductive and hormonal environment by acting on hypothalamus, pituitary and reproductive organs. Fewer studies have been carried out on pesticide residues in body fluids especially blood and semen in breeding bulls. Methods: Study was done to assess the pesticide residues in blood in relation to the endocrine profile in crossbred breeding bulls. Nineteen blood samples were collected and were allowed to clot overnight; serum was separated and stored at -20C until analysis. The samples were analyzed for the pesticide residues using gas chromatography (GC) for seven organochlorine pesticides (OCPs) namely Heptachlor epoxide, Chlordane, Fipronil, Lindane, Methoxychlor, op-DDT and Endrin and eleven organophosphorus pesticides (OPPs) namely Chorpyrifos, Dichlorovos, Ethion, Monocrotophos, Malathion, Parathion-methyl, Profenphos, Phorate, Triazophos, Quinalphos and Phosalone and four synthetic pyrethroids (SPs) namely Cypermethrin, Permethrin, Deltamethrin, Cyhalothrin. Result: The blood samples of these bulls were found positive for organophosphate-phosalone and around 73.68% of the bulls were positive for phosalone at a retention time of 13.837 min. The concentration of phosalone in the blood of crossbred breeding bulls was found to be 1.89±0.98 ng/ml. In the present study, the blood hormonal profile of pesticide residues was analyzed and it showed a significant increase in the level of Estrogen there by decreasing the testosterone: estrogen ratio. The decreased testosterone: estrogen ratio may be attributed to the detection of phosalone in blood. [ABSTRACT FROM AUTHOR]

Developing simple, efficient, and inexpensive method for trace amount organophosphorus pesticides' (OPs) detection with high sensitivity and specificity is of significant importance for guaranteeing food safety. Herein, an Ag/Au bimetallic nanoparticle-based acetylcholinesterase (AChE) surface-enhanced Raman scattering (SERS) biosensor was constructed for in situ simple and sensitive detection of pesticide residues in food. The principle of this biosensor exploited 4-mercaptophenylboronic acid (4-MPBA)-modified Ag/Au bimetallic nanoprobes as SERS signal probe to improve sensitivity and stability. The combination of AChE and choline oxidase (CHO) can hydrolyze acetylcholine (ATCh) to generate H2O2. The product of H2O2 selectively oxidizes the boronate ester of 4-MPBA, decreasing the Raman intensity of the B-O symmetric stretching. In the presence of OPs, it could inhibit the production of H2O2 by destroying the AChE activity, so the reduction of the SERS signal was also alleviated. Based on the principle, an Ag/Au bimetallic nanoparticle-based AChE SERS sensor was established without any complicated pretreatments. Benefiting from the synergistic effects of Ag/Au bimetallic hybrids, a linear detection range from 5×10−9 to 5×10−4 M was achieved with a limit of detection down to 1.7×10−9 M using parathion-methyl (PM) as the representative model of OPs. Moreover, the SERS biosensor uses readily available reagents and is simple to implement. Importantly, the proposed SERS biosensor was used to quantitatively analyze OP residues in apple peels. The levels of OPs detected in real samples by this method were consistent with those obtained using gas chromatography–mass spectrometry (GC–MS), suggesting the proposed assay has great potential applications for OPs in situ detection in food safety fields. [ABSTRACT FROM AUTHOR]

In this study, nanostructured gold was successfully prepared on a bare Au electrode using the electrochemical deposition method. Nanostructured gold provided more exposed active sites to facilitate the ion and electron transfer during the electrocatalytic reaction of organophosphorus pesticide (methyl parathion). The morphological and structural characterization of nanostructured gold was conducted using field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), which was further carried out to evaluate the electrocatalytic activity towards methyl parathion sensing. The electrochemical performance of nanostructured gold was investigated by electrochemical measurements (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)). The proposed nanostructured gold-modified electrode exhibited prominent electrochemical methyl parathion sensing performance (including two linear concentration ranges from 0.01 to 0.5 ppm (R2 = 0.993) and from 0.5 to 4 ppm (R2 = 0.996), limit of detection of 5.9 ppb, excellent selectivity and stability), and excellent capability in determination of pesticide residue in real fruit and vegetable samples (bok choy and strawberry). The study demonstrated that the presented approach to fabricate a nanostructured gold-modified electrode could be practically applied to detect pesticide residue in agricultural products via integrating the electrochemical and gas chromatography coupled with mass spectrometry (GC/MS-MS) analysis. [ABSTRACT FROM AUTHOR]

The use of pesticides adversely affects the chemical and ecological condition of water resources. The Water Framework Directive (WFD), developed for the conservation and improvement of water resources, is the most current and valid environmental legislation in Europe. WFD aims to achieve a good chemical and ecological status in all water resources. Parameters mainly used to assess chemical and ecological status are respectively priority substances and specific pollutants. Most of the substances classified as priority substances and specific pollutants are pesticides, making them key contaminants according to WFD requirements. The aim of this study is to monitor pesticide residues in the Büyük Menderes River, Turkiye. Monthly samples were collected for the duration of three years, from January 2016 to December 2018, on six different monitoring points. The most frequently detected pesticides in the river water samples were: imidacloprid, acetamiprid, parathion-methyl, dimethoate, metolachlor, clopyralid, carbendazim, and piperonyl butoxide. Since the limit values have been exceeded due to the current pressures in the basin, it is of high importance to take the necessary precautions to prevent the pesticides reaching the body of water. [ABSTRACT FROM AUTHOR]

In Senegal, the onion is one of the most consumed vegetables because it is used in all salty culinary preparations. The objective of the study was to assess the contribution of imported onions to exposure to pesticide residues and metallic trace elements. Composite samples of onions were taken in the seven largest markets of Dakar: Thiaroye, Keur Massar, Castors, Cambérene, Rufisque, Tilène and Dalifort. The metallic trace elements were determined by the ICP-AES, type Agilent Technology serial number AU 14110053 of 2014, while pesticide residues were detected and quantified by gas chromatograph, type Agilent Technology 6890A serial CN10721019, equipped with an Electron Capture micro-Detector with serial number 022423. The average content of the composite samples in lead (Pb) (778.22 µg/kg) was 7 to 8 times higher, in cadmium (Cd) (12.43 µg/kg) 5 times lower than the maximum residue limits determined by the European Union and the Codex Alimentarius, while the average concentration of aluminum (Al) was 13570 µg/kg. Twenty four (24) pesticide residues were tested. The average concentrations of some pesticides banned in European Union (EU) exceeded the maximum limits set by them. In fact, they are more than hundred (100) times higher for Prophenophos (2088.16 µg/kg), 25 times for Fenthion (508.01 ppb), 7 times for Tetramethrin (72.56 µg/kg), 2.5 times for Parathion methyl (50.16 ppb), 2 times for Dichlorvos (19.12 µg/kg), and 1.4 times for Endrin (14.26 µg/kg). The Dimetoate and the Malathion, although 21224 authorized, were found in onions at concentrations 25 times (250.8 µg/kg) and 2 times (40.71 µg/kg), respectively higher than the maximum limits set by the EU. Only the average content of Chlorpyrophos (4.13 µg/kg), Bifenthrin (2.99 µg/kg), Lambda Cyhalothrin (7.30 µg/kg) and Cypermethrin (8.095 ppb) were in accordance with the EU regulations. The results of the exposure assessment reveals that the calculated daily consumption of 0.158 kg of these onion samples by a 60 kg average body weight Senegalese adult would provide 56% of the Toxicological Reference Value for lead, 25% for aluminum, 66% for Dimetoate, 63% for Dichlorvos, 28% for Dieldrin, 19% for Fenthion, 18% for Endrin and Prophenophos and 13% for Parathionmethyl. This study reveals that the imported onion contributes to the exposure of the Senegalese adult to eight (8) phytosanitary active substances and three (3) metallic trace elements. Thus, the health risk cannot be ruled out and it is important to set up a monitoring plan for the imported onion. [ABSTRACT FROM AUTHOR]

• A novel Fe 3 O 4 @NH 2 -MIL-101(Fe)@Ag SERS nanosensor was synthesized. • Aminated-MOF grew more Ag nanoparticles with stronger affinity for analyte. • The nanosensor exhibited good SERS sensitivity, reproducibility and stability. • The substrate was effective for trace detection of organophosphorus pesticides. The unreasonable use of organophosphorus pesticides leads to excessive pesticide residues in food, seriously threatening public health, and the potential of surface-enhanced Raman spectroscopy (SERS) technology, incorporating a metal–organic framework, is substantial for the rapid detection of trace pesticide residues. Here, a novel Fe 3 O 4 @NH 2 -MIL-101(Fe)@Ag (FNMA) SERS nanosensor was developed. Results indicated that the FNMA had a high enhancement factor of 1.53 × 108, a low limit of detection (LOD) of 4.55 × 10−12 M, and a relative standard deviation of 7.73 % for 4-nitrothiophenol, demonstrating its good SERS sensitivity and uniformity, and also possessed good storage stability for one month. In quantifying fenthion and methyl parathion in standard solutions and apple juice in the range of 0.05/0.02–20 mg/L, it showed LODs of 3.02 × 10−3 mg/L and 1.43 × 10−3 mg/L, and 0.0407 and 0.0075 mg/L, respectively, demonstrating potentials in ultrasensitive trace detection of pesticides in food. [ABSTRACT FROM AUTHOR]

We proposed a simple and feasible strategy to fabricate the nano-structured cerium oxide (CeO 2) nanoparticles decorated single-walled carbon nanotubes networks (SWCNT@CeO 2), which was utilized to fabricate the SWCNT@CeO 2 /GCE sensor for detecting methyl parathion (MP) with high sensitivity. SWCNT possessed the unique one-dimensional hollow nanostructure with excellent conductivity performance, which boosted the charge diffusion rate. CeO 2 with good biocompatibility and high catalytic capacity could achieve the adsorption of MP molecules on the surface of sensing electrode due to the affinity of CeO 2 nanoparticles towards the phosphate groups of MP. Furthermore, SWCNT could effectively make up for the inherent disadvantage of CeO 2 nanoparticles in the term of electrical conductivity. The fabricated SWCNT@CeO 2 /GCE sensor achieved the ultrasensitive MP electrochemical analysis property (LOD: 9.12 nM). The satisfactory repeatability, reproducibility, anti-interference abilities were obtained at the fabricated sensor. Regarding the electrochemical detection of MP in real food samples, both satisfactory recovery rates of 87.68–107.31% and low RSD of 1.09–2.65% suggested the favorable application prospect of SWCNT@CeO 2 /GCE sensor in the field of pesticide residue analysis. • Multifunctional SCN@CeO2 nanocomposite was prepared by ultrasonic-assisted strategy. • SCN@CeO2/GCE sensor was firstly developed for the ultrasensitive analysis of MP. • SCN and CeO2 had synergistic effect in enhancing the MP analysis performance. • SCN@CeO2/GCE sensor exhibited a low MP detection limit of 9.12 nM. • SCN@CeO2/GCE sensor showed good practicality in food samples. [ABSTRACT FROM AUTHOR]

Residues of pesticides in agricultural by-products may cause harm to human health. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and a competitive form of lateral-flow immunochromatographic (LFIC) strip were developed for the determination of methyl parathion and triazophos in agricultural by-products. In the optimized system for ic-ELISA, the limits of detection (LODs) for methyl parathion and triazophos were 1.39 and 1.94 ng/mL. The linear ranges for methyl parathion and triazophos were from 7.90 to 200 ng/mL and 4.47 to 170.19 ng/mL. The recoveries from agricultural by-products ranged from 84.16 to 106.96% and the coefficients of variation were from 0.77 to 6.45%. In the optimized LFIC system, good linearity was obtained for methyl parathion and triazophos between 5 and 200 ng/mL. The LODs of the CG-LFIC strip for methyl parathion and triazophos were 2.17 and 4.21 ng/mL. The coefficients of variation of the test strip were from 0.73 to 8.34%. Pears, apples, cucumbers, and lettuces spiked with methyl parathion and triazophos were employed to characterize matrix effects using the LFIC strip. The ic-ELISA and LFIC strip were simple and practical for the rapid determination of organophosphorus pesticides in agricultural by-products. Furthermore, the LFIC strip was suitable for on-site testing and rapid screening. [ABSTRACT FROM AUTHOR]

The simple and rapid commercial colloidal gold test strip can only be used for qualitative or semi-quantitative detection, accompanied by weak detectability and false negative experimental results. Herein, a photothermal test strip assay which combined test strip with a portable photothermal card reader was established to achieve quantitative detection with excellent detectability. According to the photothermal effect produced by gold nanoparticles (GNPs) captured on the test line, the signal could be recorded by the reader. Thirteen food hazards including veterinary drug residues and pesticide residues were tested; the photothermal detectability in actual samples were about 23 (methyl parathion), 7 (enrofloxacin), 6 (sarafloxacin), 8 (sulfadiazine), 12 (sulfamethazine), 7 (paraquat), 6 (malachite green), 11 (amantadine), 13 (nitrofurazone), 6 (diethylstilbestrol), 12 (estriol), 21 (estrone), and 26 (17β-estradiol) times better than the visual detectability. Our results demonstrated that the photothermal test strip assay could be used for sensitive, rapid, and quantitative detection of residues of food hazards. [ABSTRACT FROM AUTHOR]

In this work, a new type of Au-tetrahedral DNA nanostructure (Au-TDN) was originally proposed and successfully applied in an electrochemiluminescence aptasensor to detect organophosphorus pesticides (Ops). The aptamers modified with –SH could be covalently bonded with gold nanoparticles (AuNPs) to form a tetrahedron structure, and there were independent probes at each vertex of the tetrahedron, which could increase the probability of specific binding with Ops. The originally designed structure could not only maintain a stable tetrahedral configuration, but also combined with the target to improve the sensitivity of the sensor. Meanwhile, silver nanoparticles (AgNPs) could catalyze the chemical reaction between luminol and H2O2 to generate a variety of intermediates called reactive oxygen species (ROS) for signal enhancement. Factors that had important influences on the aptasensor, such as the concentration of Au-TDN, the incubation time, and the pH value of the buffer, were optimized in this trial. According to the final results, the limit of detection (LOD) of 3 pg mL−1 (S/N = 3) for methyl parathion, the LOD of 0.3 pg mL−1 (S/N = 3) for parathion and the LOD of 0.03 pg mL−1 (S/N = 3) for phoxim were obtained, respectively. Moreover, the novel tetrahedral structure could be replaced by different types of aptamers to expand its application range and lay a foundation for the development of portable rapid detection devices for pesticide residues. [ABSTRACT FROM AUTHOR]

[Display omitted] • PDDA functionalized AuNPs@p-COFs nanocomposite was successfully synthesized by a facile strategy. • The biosensor was fabricated by taking full advantage of the synergistic effect of nanocomposite. • The fabricated biosensor displayed excellent performance for MP detection. • The study provides insights into design of multifunctional sensing platform. Organophosphorus pesticides (OPs) residues in agricultural products such as vegetables, fruits, and grains pose a threat to food safety and human health. In this work, a novel and highly sensitive electrochemical biosensor was developed for OPs residues detection in real sample, based on the immobilization of acetylcholinesterase (AChE) by electrostatic adsorption on a glassy carbon electrode (GCE) modified with composite nanomaterials of porphyrin-based covalent organic frameworks (p-COFs) loaded by gold nanoparticles (AuNPs) and poly (diallyldimethylammonium chloride) (PDDA). Due to the synergistic effect of p-COFs, AuNPs and PDDA, the fabricated biosensor displayed the remarkable properties with the high electrocataytic activity, and excellent biocompatibility, resulting in a significant signal amplification of as-prepared biosensor. Under optimized conditions, the biosensor showed excellent sensing performances for the detection of methyl parathion (MP), with wide linear ranges from 1.9 × 10−9–3.8 × 10−5 M and a low detection limit as low as 2.3 × 10−10 M, as well as the satisfactory selectivity, excellent reproducibility, anti-interference properties and good stability. It was also successfully applied to the monitoring of MP content in vegetables and fruits, which may be explore a new opportunity for the potential utilization in analysis field. [ABSTRACT FROM AUTHOR]

This study investigated the occurrence and seasonal distribution of different classes of pesticides in surface waters of the Ondas River Watershed, as well as potential risks to the aquatic health and human water consumption in the western region of Bahia state, Brazil. Two gas chromatography-mass spectrometry analytical methods were applied to monitor 34 pesticides in water samples collected during both the dry and rainy seasons at 17 sites. Upon individual analysis, only γ-HCH, methoxychlor, demeton-S, methyl parathion, fenitrothion, chlorpyrifos, and azoxystrobin exhibited statistically significant differences between seasons. During rainy season, concentration medians of residues were higher for γ-HCH (74.7 ng L−1), methoxychlor (25.1 ng L−1), and azoxystrobin (47.2 ng L−1), potentially linked to historical contamination or illegal use. Conversely, pesticides like methyl parathion, fenitrothion, and chlorpyrifos, belonging to the organophosphate class, showed higher concentration medians in the dry period, measuring 75.1, 5.50, and 10.8 ng L−1, respectively, probably due to region crop activities. The risk quotient (RQ) assessment for aquatic life indicated that 59.0% of the samples in the dry season and 76.0% in the rainy season had RQ values greater than one, signifying a critical scenario for species conservation. Regarding human consumption, elevated risks were observed for heptachlor in both sampling periods and for azoxystrobin during the rainy season, surpassing RQ levels above 1, indicating danger in untreated water ingestion. Additionally, 24.0% and 53.0% of the samples in the dry and rainy seasons, respectively, contained at least one pesticide exceeding the EU resolution limit (100 ng L−1). Therefore, considering this information, implementing mitigation measures to avoid the river's contamination becomes imperative. [Display omitted] • 34 pesticides in surface waters of the Ondas River Watershed (ORW) under study. • Pesticide residues has been found widely distributed in the ORW. • Each pesticide residue was quantified in at least one sample. • Heptachlor exceeds the maximal permitted level in Brazilian and EU laws. • The risk quotient (RQ) assessment indicated a critical scenario for aquatic life. [ABSTRACT FROM AUTHOR]

Methyl parathion (MP), as a typical organophosphorus pesticide, has been widely used in pest control and plant growth regulation. Simultaneously, the problem of pesticide residues also poses a serious threat to the environment and human health. Currently, pesticide residue detection technology still faces great challenges in practical applications due to the problems of expensive facilities and complicated operations in conventional analysis methods. To address these problems, a novel nonenzymatic electrochemical pesticide sensor was reported. A zirconium-based metal organic framework material with terephthalic acid as a ligand (Zr-BDC) was designed to combine with electro-reduced graphene oxides (rGO). The Zr-BDC-rGO nanocomposite contains Zr-OH groups with high affinity for phosphate groups, endowing it with selective recognition and a higher adsorption capacity for MP. Moreover, rGO has a high specific surface area and excellent electron transport capability, making it an excellent functionalized adsorption and substrate material, which could improve the conductivity of the material and achieve a lower detection limit. Upon optimization, this sensor provided a wide linear range from 0.001 to 3.0 μg mL−1 and low limit of detection 0.5 ng mL−1 for MP. This work provides a rapid, sensitive and cost-effective sensing platform for pesticide residue detection. [ABSTRACT FROM AUTHOR]

Background: Pesticides act as endocrine disruptors and cause enormous disturbances in steroidogenesis, spermatogenesis and sexual behavioural display. These toxicants modulate and/or disrupt the reproductive and hormonal environment by acting on hypothalamus, pituitary and reproductive organs. Few studies have been carried out to assess the levels of pesticides in dairy cattle/ buffaloes. The information on pesticide residues in body fluids especially blood and semen in breeding bulls is lacking. Method: In the light of above background nineteen fresh semen ejaculates were collected from Milkfed, Khanna and PLDB (Punjab Livestock Development Board), Nabha, Punjab and stored at -80°C. Immediately after collection, the semen was centrifuged at 4500 x g for 20 min at 4°C. The supernatant (seminal plasma) was stored at -20°C until processing for the assessment of pesticide residues using gas chromatography (GC). In the present study on crossbred breeding bulls, the semen samples were analyzed for organochlorines, organophosphates and synthetic pyrethroid pesticide residues. Seven OCP were screened namely Heptachlor epoxide, Chlordane, Fipronil, Lindane, Methoxychlor, op-DDT, Endrin. Eleven OPP were screened namely Chorpyrifos, Dichlorovos, Ethion, Monocrotophos, Malathion, Parathion-methyl, Profenphos, Phorate, Triazophos, Quinalphos and Phosalone and four SP's namely Cypermethrin, Permethrin, Deltamethrin, Cyalothrin were screened in the semen samples. Semen samples were also assessed for viability, HOST (%) and abnormality (%) for both fresh as well as post thaw samples. Result: None of the semen samples were found positive for any of the above pesticide residues. This may be attributed to the feeding of fodder cultivated at the stations without using any pesticides, hence no pesticide residue found in the semen samples of the crossbred breeding bulls of these semen stations in present study, viability (%) of sperms were found to be significantly higher (p<0.05) in fresh (75.57±5.31) as compared to post thaw (70.17±4.64) semen of bulls. The abnormality (%) of sperms was found to be significantly lower (p<0.05) in fresh (13.61±3.71) than post thaw (18.22±3.59) semen bulls. Also in present study the host (%) was found 67.23±4.76 in fresh semen which decreased to 46.82±3.55 in post thaw semen. [ABSTRACT FROM AUTHOR]

Accurately detect the residues of organophosphate pesticides (OPs) in food and environment is critical to our daily lives. In this study, we developed a novel acetylcholinesterase (AChE) biosensor based on Au–Tb alloy nanospheres (NSs) for rapid and sensitive detection of OPs for the first time. Au–Tb alloy NSs that with good conductivity and biocompatibility were produced with a mild hydrothermal. Under optimal conditions, the AChE biosensor was obtained by a simple assembly process, with a big linear range (10−13–10−7 M) and the limit of detection was 2.51 × 10−14 M for the determination of methyl parathion. Moreover, the determination of methyl parathion with the prepared biosensor presented a high sensitivity, outstanding repeatability and superior stability compared with other reported biosensors. Through the determination of tap water and Yanming lake samples, it was proved that the modified biosensor with satisfactory recoveries (96.76%–108.6%), and are realizable in the determination of OPs in real samples. [ABSTRACT FROM AUTHOR]

The present study evaluates the efficacy of ozonated water for the removal of pesticide residues in grapes and green bell peppers. Fruit fortified with pesticides (azoxystrobin, chlorothalonil, chlorpyrifos, cypermethrin, hexaconazole and methyl parathion) were subjected to 15 and 30 min aqueous ozone treatment. GC analysis of ozonated fruits showed a 48.67% to 96.95% decrease in pesticide residues of different pesticides. Methyl paraoxon, a toxic degradation product of methyl parathion, was detected in the ozonated water sample. To assess the effect of ozonation on the nutraceutical quality of fruits, the concentrations of eleven polyphenols and ascorbic acid were analyzed. The individual polyphenols showed different trend in 15 and 30 min treatment. Overall, there was an increase in the levels of all the polyphenols in grapes after 30 min ozonation treatment. In peppers, there was a net increase in quercetin, quercetin-3-O-glucoside, rutin and kaempferol in 30 min while other polyphenols were decreased. The ascorbic acid content of both the fruits was decreased by more than 70% upon ozonation. Thus, ozonation treatment was effective in pesticide removal. However, it changed the nutraceutical quality of grapes and green bell peppers. [ABSTRACT FROM AUTHOR]

Nanomaterial represents a principal driver to the adoption of electrochemical sensors for pesticides residues in water. Thus, the current strategy reports facile and highly sensitive electrochemical probe for monitoring parathion residues in water. The probe was based upon the use of Au nanoparticles (AuNPs) functionalized Nafion nanocomposites modified glassy carbon electrode (Au NPs/Nafion/GCE). The surface morphology, effective surface area and electrocatalytic performance of the Au NPs/Nafion/GCE were recorded and assigned using a scanning electron microscopy (SEM), cyclic voltammetry (CV) and electronic spectra. A straightforward protocol based upon combination of Au NPs/Nafion/GCE and square wave- adsorptive cathodic stripping voltammetry at pH 7.0 was established for parathion detection. The probe displayed two linear responses between the catholic peak current (i p,c) at − 0.8 V versus parathion concentrations over the ranges from 1.07 × 10−6 - 1.07 × 10−5 and 1.99 × 10−9 - 9.0 × 10−7 M with limits of detection (LOD) and quantification (LOQ) of 6.06 × 10−10 M and 2.0 × 10−9 M, respectively. The probe exhibited excellent reproducibility, repeatability with RSD of ± 0.5% (n = 5) at 8.0 × 10−7 M parathion. The probe was applied for parathion detection in water and validated by HPLC. The experimental Student t exp and F exp values were less than the tabulated t tab (2.78) and F tab (6.39) at 95% probability. • A cost-effective voltametric sensor for the detection of parathion residues is presented. • Long-term stability of parathion -based electrochemical sensor was achieved. • The sensor displayed excellent figures of merits and limit of detection. • Electrocatalytic activity of Au NPs -Nafion improved the sensitivity. • Good selectivity and long-term stability towards parathion in real samples. [ABSTRACT FROM AUTHOR]

The abuse of pesticides is apt to cause residue issues. In this study, an electrochemical sensing platform was developed using N-doped reduced graphene oxide (N-rGO) loaded with the Pd-doped lanthanum vanadate (Pd-LaV) to simultaneously detect two pesticides: carbendazim (CBZ) and parathion methyl (MP). The results demonstrated that N-doping can not only enhance the electron transport and catalytic ability of rGO, but also avoid the aggregation of Pd-LaV. Moreover, Pd compensated for the insufficient conductivity of LaV, fulfilling the catalytic performance of LaV better played out. N-rGO/Pd-LaV possessed abundant active groups, reaction sites, and effective interaction, which served its charge transfer rate and electrocatalytic ability as superior. In individual detection, LODs of CBZ and MP were 2.42 nmol/L and 1.85 nmol/L, respectively. In simultaneous detection, LODs of CBZ and MP were 1.94 nmol/L and 1.71 nmol/L, respectively. Finally, the sensing platform was applied to water and vegetable juice samples. [Display omitted] • LaV with high conductivity was synthesized by Pd-introducing. • rGO with high catalytic ability was prepared by hydrothermal N-doping. • The uniform distribution of Pd-LaV was achieved with the support of N-rGO. • The proposed sensor can simultaneously detect two pesticides accurately. • The LODs of the proposed sensor were as low as nanomolar per liter. [ABSTRACT FROM AUTHOR]

It is of great significance to develop a simple and effective method for constructing large-scale high-quality surface-enhanced Raman scattering (SERS) substrate. Here, an Ag nanoparticle-assembled micro-bowl array was prepared by a close-packed polystyrene (PS) sphere monolayer templated electrodeposition approach. The fabricated Ag nanoparticle-assembled micro-bowl array shows high SERS sensitivity to rhodamine 6G (R6G) under an ultra-low concentration of 1 fM, and exhibits excellent SERS spectral uniformity with a small relative standard deviation (RSD) of 7.6% and good reproducibility (a RSD ∼8.2% for the average peak intensities from different batches of SERS substrates). The fabricated micro-bowl array SERS substrate was employed to detect pesticide residue (thiram and methyl parathion) on vegetables. The limit of detections (LODs) for the two pesticides are lower than the maximum residue limits (MRLs) set by the European Union respectively, showing promising application in rapid inspection of food safety. [ABSTRACT FROM AUTHOR]

This research is a case study on detection of pesticides in river water, sediment as well as fish samples from Tapi River, among the major rivers of Gujarat, India. To investigate the misuse, concentration level and occurrence patterns of persistent pesticides, samples were collected from the river. Chlorpyrifos, methyl parathion, hexachlorocyclohexane (HCH), dichloro diphenyl trichloroethane (DDT) and endosulfan were analyzed by gas chromatography technique with flame ionization detector (FID). Scanty reports are available, but after 1999, no such data are reported as some of these pesticides have been banned. Although these pesticides are still in use which we observed from the obtained results. In this river, the amount of endosulfan, chlorpyrifos, and methyl parathion was observed in surface water with concentrations of 37.56 µg/L, 0.86 µg/L and 0.43 µg/L, respectively. Endosulfan, DDT and methyl parathion detected in sediment were 38.38 ng/g, 0.65 ng/g and 0.77 ng/g, respectively. In fish samples, levels of endosulfan, chlorpyrifos, and methyl parathion detected were 101.28, 0.392, and 3.49 ng/g correspondingly. Results showed that highly toxic pesticides are still being used in the surrounding area, and there is an urgent need for enforcement of rules to control the production and application of such pesticides. [ABSTRACT FROM AUTHOR]

In this study, we used 2-(diethexyphosphoryl)acetic acid as a common template molecule and Fe3O4@SiO2 as support material to prepare a superparamagnetic core/shell molecular imprinting polymer (MIP), Fe3O4@SiO2@MIP, which has multiple recognition sites and increased adsorption capacity. Then, a biomimetic fluorescence immunoassay method was developed for the simultaneous determination of methyl parathion, chlorpyrifos, and trichlorfon using the Fe3O4@SiO2@MIP as biomimetic antibody and quantum dots as label. The factors that influenced the performance of this method were optimized. Under optimal conditions the limits of detection of the method were 0.21 ± 0.021, 0.44 ± 0.069 and 0.32 ± 0.033 μg/L for methyl parathion, chlorpyrifos, and trichlorfon, respectively. To evaluate the accuracy of the method, apple and orange samples spiked with methyl parathion, chlorpyrifos, and trichlorfon were analysed, and the recoveries ranged from 73.1% to 119.3%. Finally, this method was applied to detect three pesticides in pear, carrot, kiwifruit, and banana samples, and the results indicated a good correlation with those obtained from gas chromatography method. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to present a novel and cost-effective optical biosensor design by simple preparation method for detection of "parathion-methyl," which is a model pesticide pose to public health and the environment. Design/methodology/approach: The optical enzyme biosensor (TCA) for detection of pesticide "parathion-methyl" was developed on the basis of immobilization of tyrosinase enzyme on chitosan film by adsorption technique. The analytic performance of TCA was investigated by measuring its activity with Ultraviolet (UV) visible spectrophotometer. Findings: Uniform porous network structure and protonated groups of chitosan film provided a microenvironment for tyrosinase immobilization evident from Fourier transform infrared (FTIR) spectroscopy and Atomic Force Microscopy analysis. TCA has a wide linear detection range (0-1.03 µM) with high correlation coefficient and it can detect the parathion-methyl concentration as low as 159 nM by noncompetitive inhibition kinetics. Using the TCA sensor both for ten times and at least 45 days without a significant loss in its activity are the indicators of its good operational and storage stability. Moreover, TCA can be applicable to tap water, providing a promising tool for pesticides detection. Originality/value: This is the first time to use the in situ analytical technique that can improve the performance of optical enzyme sensor provided to control the pesticide residue better with respect to traditional techniques. The effect of organic solvents on the performance of optical enzyme biosensor was investigated. Inhibition kinetic of the solvents rarely encountered in literature was also studied besides the pH and temperature tolerance of the optical biosensor. [ABSTRACT FROM AUTHOR]

• PDADMAC/PSS/Au@Ag NRs filter paper is a kind of disposable environment-friendly flexible SERS substrate. • The PDADMAC/PSS modified filter paper showed the potential of SERS substrate for nanoparticle self-assembly. • The prepared paper-based SERS substrate had high SERS activity and good reproducibility. • PDADMAC/PSS/Au@Ag NRs filter paper realized the "paste-reading" detection of MP, TMTD and CPF on the pericarp. The goal of food safety supervision is to directly identify the pesticide residues on the surface of fruits and vegetables. This study proposed to develop a facile, non-destructive, and sensitive method based on surface-enhanced Raman scattering (SERS) to detect non-systemic pesticides on the surface of fruits and vegetables. The composite material was prepared by loading CTAB guided Au@Ag NRs with positive charge onto filter paper which was modified with PDADMAC(+) and PSS(−) using electrostatic adsorption. Au@Ag NRs with bimetallic synergies were effectively adsorbed in the fiber grid to generate 3D SERS hotspots within a few microns of depth. The results showed that the 3D composite flexible substrate had a high SERS activity, great repeatability, and sensitivity when the method was utilized to detect 4-MBA, methyl-parathion, thiram and chlorpyrifos. Three kinds of non-systemic pesticides on the peel could be detected directly and quickly owing to the arbitrary bending of the substrate, demonstrating the efficiency of the SERS "paste-reading" method. The acquired findings demonstrated that PDADMAC/PSS/Au@Ag NRs composite filter paper had the potential to provide rapid feedback for in- situ analysis of pesticide residues on the surface of fruit and vegetable. [ABSTRACT FROM AUTHOR]

[Display omitted] • The MAC-ZIF-8 was successfully synthesized for the immobilization of CRL. • The biosensors can be used to detect methyl parathion and chlornitrofen residues. • The biosensors demonstrated wide linear range, low LOD and good recovery rate. • The biosensors showed good reusability after scanning continuously for 100 times. The high toxicity and bioaccumulation effects of nitroaromatic pesticides and their serious environmental risks have led to a sharp increase in public concern about pesticide residues. Present work developed a direct, rapid, sensitive and reliable Candida rugosa lipase (CRL)@ the ordered macro-microporous ZIF-8 (MAC-ZIF-8) nanofibers biosensor (CRL@MAC-ZIF-8 nanofibers) for methyl parathion and chlornitrofen residues detection in lake water. The biosensors fabricated by the CRL@MAC-ZIF-8 nanofibers demonstrated wide linear range for both methyl parathion (0.5–114 µM) and chlornitrofen (1–40 µM) detection. The biosensors also demonstrated good reusability for methyl parathion detection with retainment of more than 97% of its initial response after scanning continuously for 100 times. During 1 month storage stability test at 4 °C, the fabricated biosensor demonstrated excellent stability for methyl parathion detection with retainment of 86%-100% of its initial response. Meanwhile, the biosensors also demonstrated good recovery rates when the biosensors were used to detect methyl parathion and chlornitrofen residues in lake water sample. [ABSTRACT FROM AUTHOR]

Abstract The extensive use of pesticides in agriculture has become a very common practice in developing countries like India. Consequently, the increased concentration of residues of these hazardous pesticides in fruits and vegetables is manifested. The study aimed to assess the health hazards associated with the presence of pesticide residues in fruits and vegetables sampled from farms and markets of Kinnaur district of Himachal Pradesh (India). Residues of predominant pesticides used in the region, belonging to the group of organophosphates, pyrethroid and phthalimide, were analysed using gas chromatograph quadrupole mass spectrometer (GC-MS/MS). The pesticide extraction from the matrix was done following the modified QuEChERS method. Results indicated varying concentrations of pesticide residue in market and farm samples with farm samples more contaminated than market samples. Chronic health hazards prediction indicated that organophosphorus groups (methyl parathion and triazophos) posed health risk to children in the study area. Graphical abstract Image 1004 Highlights • Extensive use of pesticides, contaminate the food which can lead to serious health hazards. • Farm fruits and vegetables contained higher pesticide residues in comparison to market samples. • Residues of methyl parathion and triazophos in fruits and vegetables pose health risk. • Children are more vulnerable to health risk in the region. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new MOF-based SERS substrate of Fe 3 O 4 @UiO-66(Zr)@Ag NPs was synthesized. • Component advantages in the substrate were brought into play synergistically. • The substrate had excellent SERS detection sensitivity, uniformity and stability. • The substrate realized organophosphorus trace detection in water and apple juice. Surface-enhanced Raman spectroscopy (SERS) technology has been revived and developed with the introduction of metal–organic frameworks (MOFs), while more valuable properties of MOFs for SERS substrates remain largely unexplored. This work constructed a new SERS substrate Fe 3 O 4 @UiO-66(Zr)@Ag nanoparticles (FUAs) with excellent SERS detection sensitivity, uniformity, reproducibility and stability, exhibiting a high Raman enhancement factor (5.62 × 106), low limit of detection (LOD, 2.11 × 10-11 M) and RSD (12.41 %) for 4-NBT, and maintaining 81 % SERS activity within 60 days. The FUAs took full advantage of the strong affinity of UiO-66(Zr) for organophosphorus pesticides (OPs) to realize trace OPs detection. The LODs of phoxim, triazophos and methyl parathion in apple juice were 0.041, 0.021 and 0.0031 mg/L, respectively, with good linearities ranging from 0.02 or 0.1–50 mg/L, meeting the requirements of the food control standards, indicating that the potentials and prospects of the FUAs SERS substrate for trace detecting OPs in foods. [ABSTRACT FROM AUTHOR]

Developing electrode materials with excellent electrocatalytic properties for detecting pesticide residues plays a vital role in the safety of agricultural products and environmental applications. Herein, we designed a new electrochemical sensor on the basis of N-doped carbon hollow nanospheres modified with Sn/MoC Schottky junction (Sn/MoC@NC) for methyl parathion (MP) detection. The Sn/MoC@NC was prepared by self-assembled polymerization-anchoring strategy and high-temperature carbonization design. Sn/MoC Schottky junction and hollow nanosphere structure endow Sn/MoC@NC with a larger surface area, more active sites, and faster electron transfer, which is beneficial to enhancing its electrocatalytic performance. The structural characterizations and physicochemical properties of Sn/MoC@NC were explored through various microscopy, spectroscopic and electrochemical techniques. The experimental results confirmed that the calibration curve for current and MP concentration (0.05–10 μg/mL) was available under optimized conditions, and the sensitivity and detection limit were respectively determined to be 9.02 μA μM 1 cm 2 and 8.9 ng/mL. Furthermore, the constructed sensor displayed excellent selectivity, repeatability, and stability, which qualified it for use in detecting MP in grapes and tap water with satisfactory recovery. This work may provide some interesting prospects for constructing high-performance electrocatalysts for MP detection. [Display omitted] • Sn/MoC@NC Schottky catalyst was designed and synthesized for MP detection. • The self-assembled polymerization-anchoring strategy was proposed in this paper. • The coupling of of Schottky junction and nano hollow improve catalytic activity. • Sn/MoC@NC/GCE exhibits superior electrocatalytic reduction performance for MP. [ABSTRACT FROM AUTHOR]

A novel bifunctional antibody (BfAb) that could recognize methyl parathion and imidacloprid simultaneously was prepared by a hybrid hybridomas technique. Using the BfAb as the sole recognition reagent, a multiplexed immunochromatographic test strip based on a time-resolved chemiluminescence (CL) strategy was developed for quantitative detection of pesticide residues. Horseradish peroxidase (HRP) and alkaline phosphatase (ALP) were used as the CL probes to label the haptens of methyl parathion and imidacloprid, respectively. After the labeled haptens competed with methyl parathion and imidacloprid to bind with the BfAb immobilized on the test strip, the two CL reactions catalyzed by the enzymes were triggered simultaneously by coreactants injection. Due to the distinct CL kinetics characteristics of HRP and ALP, the signals for methyl parathion and imidacloprid detections were collected at 2.5 s and 300 s, respectively. The linear ranges for methyl parathion and imidacloprid were both 0.1–250 ng mL −1 , with detection limits of 0.058 ng mL −1 (S/N=3). The whole assay process could be accomplished within 22 min. The detection results for spiked traditional Chinese medicine samples demonstrated its application potential. The proposed method provided a low-cost, facile and rapid tool for multiplexed screening of pesticide residues using single antibody. [ABSTRACT FROM AUTHOR]

An essential aspect for the wide practical application of surface-enhanced Raman spectroscopy (SERS) lies in the further improvement of its sensitivity. In this paper, a strengthened chemical effect with a high enhancement factor (EF) of 3.9 × 107 was first triggered through simply adjusting the heterojunction structure between graphitic carbon nitride (g-C 3 N 4) flake and molybdenum disulfide (MoS 2) nanoflower. Ag nanoparticles (Ag NPs) were then photo-reduced onto the g-C 3 N 4 @MoS 2 matrix to introduce significant steric electromagnetic field under excitation, which was further reinforced by provoking a resonance coupling effect based on graphene oxide (GO) resonant cavity. Such a cavity was set between the g-C 3 N 4 @MoS 2 @Ag-polydimethylsiloxane (PDMS) matrix and the Ag nanocubes (Ag NCs)-embedded PDMS coating membrane, facilitating a robust flexible SERS chip with a promising EF attained as 1.1 × 109. Additionally, the SERS intensity was only decreased by 5% after three months, indicating the excellent stability of the as-prepared bilayer SERS chip. The on-site reclaimable monitoring for thiram (TMTD) and methyl parathion (MP) accompanied by a low limit of detection (LOD) of 10−6 mg/mL was achieved by utilizing the proposed sophisticated SERS chip, demonstrating its fascinating application feasibility. [Display omitted] • A structure-ameliorated chemical enhancement was triggered by the heterojunction of g-C 3 N 4 flake and MoS 2 nanoflower. • A remarkable electromagnetic resonant effect with a high EF of 1.1 × 109 was facilitated by nanoscale GO resonant cavity. • The versatile bilayer membrane chip demonstrated an on-site reclaimable monitoring of pesticides with a LOD of 10−6 mg/mL. [ABSTRACT FROM AUTHOR]

Pesticide residues have raised serious public concern towards agriculture, environment and food safety. Recently, metal-organic frameworks (MOFs) have been employed as promising recognition and signal generation elements in sensors for pesticide detection. However, the general format of tiny particles with poor dispersity brings obstacles to detection operation and the improvement of sensing performance. Here, we report a sensor based on porous MOFs hybrid sponge for fluorescent-visible detection of methyl parathion. Benefiting from the intermediate of adhesive and porous fibrin film, MOFs are loaded with good dispersion and accessibility, thereby endowing the sensor with a rapid response time of 10-min, a wide linear detection range of 50–2500 μg L-1, and a low limit of detection of 4.95 μg L-1. Moreover, the hybrid sensor presented superior durability and anti-interference ability to the detection in complex conditions, including organic solvents, acidic solution, high temperature, and even chemical interferences. This hybrid not only provides a new construction strategy for a nanomaterial-based sensor, but also permits a portable and durable route for the detection. [ABSTRACT FROM AUTHOR]

• A novel Pd-Fe 3 O 4 /PEDOT:PSS/NS-Ti 3 C 2 T x PM sensor was prepared. • NS-Ti 3 C 2 T x was synthesized by a chemical reaction of covalent in-situ doping. • The dispersibility and continuity of NS-Ti 3 C 2 T x layers were enhanced by PEDOT:PSS. • The sensor shows high accuracy and feasibility for PM residual detection in nature. Excessive pesticide residues (e.g., parathion-methyl, PM) not only threaten human health but also cause serious environmental pollution. Herein, a palladium-magnetic iron/poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonic acid)/nitrogen and sulfur co-doped titanium carbide (Pd-Fe 3 O 4 /PEDOT:PSS/NS-Ti 3 C 2 T x) composite frameworks was fabricated, hoping to provide an interesting strategy for the design of PM sensor. First, the NS-Ti 3 C 2 T x was synthesized through N and S co-doped modification of Ti 3 C 2 T x to improve its electrical properties. The hierarchical PEDOT:PSS/NS-Ti 3 C 2 T x composite, as catalytic supports of Pd-Fe 3 O 4 , was constructed with PEDOT:PSS inserting between the NS-Ti 3 C 2 T x nanolayers to enhance the dispersibility and continuity of the layers. The components and structure of composites were well identified by various characterization and analysis methods. More importantly, the Pd-Fe 3 O 4 /PEDOT:PSS/NS-Ti 3 C 2 T x /GCE sensing platform indicates an outstanding electrocatalytic activity in the electro-reduction of PM with sensitivity of 517.08 μA mM−1 cm−2, linear detection range of 0.01–140 μM, limit of detection as 3.3 nM, and k s as 3.585 s−1. Moreover, this sensing platform was successfully applied to PM residue detection in vegetable, surface water and soil, showing high accuracy and promising feasibility in application. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A PDMS-based flexible SERS substrate modified with gold nanostars was prepared. • The substrate was used for in-situ detection of pesticide residues on fruit surfaces. • The detection limit of methyl parathion was down to 1.946 μg/mL. • The detection eliminated the requirement for sample pre-processing steps. Herein, we developed a PDMS-based flexible SERS substrate modified with gold nanostars (AuNSs) for in-situ detection of pesticide residues on fruit surfaces. AuNSs with sharp branches were assembled on aminated PDMS membrane by chemical bonding effect. The AuNSs/PDMS substrate showed good signal uniformity, stability and sensitivity using the Raman signal molecule 4-MBA and the detection concentration of 4-MBA was as low as 10−8 mol/L. Then the AuNSs/PDMS substrate was used to detect methyl parathion (MP) standard solution. A good linear relationship between SERS intensity at 1342 cm−1 and MP concentration was established in the range of 4 μg/mL–100 μg/mL, and the limit of detection was down to 1.946 μg/mL. Moreover, the AuNSs/PDMS substrate was directly covered on the surface of MP contaminated apple, and the Raman laser was incident from the back of substrate to achieve in-situ detection of pesticide residues. The recovery ratio indicated that the fabricated SERS substrate was realized successfully in real sample detection. AuNSs/PDMS substrate eliminates the requirement for sample pre-processing steps before testing, which can be used as a method for rapid inspection of pesticide in agricultural products on site. [ABSTRACT FROM AUTHOR]

[Display omitted] • Double-deck petal-like Z-NiO/CoO@CC was synthesized for MP detection. • Etching-doping sedimentation were used to introduce Ni element and keep feature. • Bimetal oxides in carbon nano-frame (ZIF-67 derived) improve catalytic activity. • The Z-NiO/CoO@CC shows the satisfying performance towards MP detection. • The mechanism for MP detection were revealed clearly. Designing efficient and rapid methods for detection of pesticide residue is one of the prerequisites to reduce its negative health influences. Herein, we constructed an electrochemical sensor for efficient detection of Methyl parathion (MP) using a double-deck petal-like NiO/CoO nanoporous carbon composite (Z-NiO/CoO@CC). The Z-NiO/CoO@CC was fabricated through etching-doping sedimentation strategy and carbonized conversion. The elaborate electrocatalyst not only created the structural advantages to offer more activities sites for the target analyte, but also had compositional virtues by combining the carbon nano-frame (originating from zeolitic imidazolate framework, ZIF-67) and bimetal oxides to enhance electrochemical performances. Besides, the electro-catalysis mechanism and detection performance of the prepared electrode were also detailly studied through different electrochemical techniques. Under optimized conditions, the prepared Z-NiO/CoO@CC showed favorable performance for MP detection with linear range from 10 ng/mL to 10 μg/mL, high sensitivity of 12.8 μA μM−1 cm−2 and low detection limit of 3.6 ng/mL (S/N = 3). Moreover, the practical feasibility of the Z-NiO/CoO@CC was also verified through monitoring MP in tap water and grape samples. This work has explored a novel method for construction of high-performance electrochemical MP sensors. [ABSTRACT FROM AUTHOR]

Inspired by the wearable sensors and to meet the demand for rapid and nondestructive detection, we developed a smart plant-wearable biosensor, which can be applied for in-situ analysis of organophosphorus pesticide on crop surfaces. Herein, the serpentine three-electrode system was prepared via the laser-induced graphene (LIG) technology. After transferred by polydimethylsiloxane (PDMS), the stretchable and flexible LIG-based electrode was obtained, which can be well adapt to the irregular surface of crops, such as leaves and fruits. After modified with organophosphorus hydrolase (OPH) and equipped with biocompatible semisolid electrolyte, our plant-wearable biosensor can selectively capture and recognize the methyl parathion and the data can be transmitted to a smartphone device wirelessly, which enable the real-time and in-situ electrochemical analysis of pesticide on the surface of agricultural products. To further enhance the electrochemical performance, gold nanoparticles (AuNPs) were modified on the surface of three-dimensional (3D) porous LIG. Such smart plant-wearable biosensor could be a transformative approach for the in-situ analysis of pesticide residue on crops, which could also promote the development of precision agriculture in the future. • A flexible serpentine three-electrode system was fabricated by laser-induced technology. • The plant-wearable biosensor can realize the nondestructive and in-situ pesticide analysis on agricultural product surfaces. • The real-time pesticide residue information can be received on a smartphone wirelessly. [ABSTRACT FROM AUTHOR]

• Ultrasonic treatment effectively enhanced the degradation of parathion methyl (PM). • The degradation of PM was properly fitted the first order kinetics. • Three degradation products of PM were determined by UPLC-QTOF/MS. • The toxicities of three degradation products of PM were evaluated. • Among the degradation products, two of them were more toxic than PM. The removal of pesticide residues in food by ultrasound has attracted more attention in recent years, and the formation of intermediate products may have some profound effects on the toxicity of treated food. Therefore, degradation of parathion methyl (PM) in bovine milk by ultrasonic treatment was studied in this paper. Results showed that the ultrasonic intensity and the initial concentration of PM had a significant effect on the degradation rate of PM (P < 0.05). The maximum degradation rate of PM was 97.10%. Three transformation products were identified through UPLC-QTOF/MS analysis, and the oxidation pathway was proposed as the consequence of ultrasonication. Furthermore, according to Quantitative Structure Activity Relationship (QSAR) model prediction, the ecotoxicity of the transformation products may be higher than that of PM. These findings showed that although ultrasonic treatment can effectively degrade pesticide residues in food, it may also generate transformation products with the higher ecotoxicity. [ABSTRACT FROM AUTHOR]

• Micro-coffee-ring patterns are fabricated on fiber facet using a self-developed laser-induced dynamic dip-coating method. • The formation mechanisms of micro-coffee-rings on fiber facet are analyzed. • These fiber SERS probes simultaneously show high detection sensitivity and good reproducibility in SERS detections. • In situ trace SERS detections in complex liquids, e.g. pesticide residues in juice and antibiotics in milk, are achieved. Coffee-ring structures, which are easy to prepare, have many hotspots for surface-enhanced Raman scattering (SERS). However, the inhomogeneous distribution of hotspots causes very poor SERS detection reproducibility, which strongly restricts their practical applications. In this paper, by combining a coffee-ring structure with the waveguide effect of optical fibers, we propose novel micro-coffee-ring-patterned fiber SERS probes fabricated by a laboratory-developed laser-induced dynamic dip-coating method. The mechanisms of micro-coffee-ring formation on fiber facet are analyzed in detail. With the help of a programmable dip-coater, micro-coffee-ring-patterned fiber SERS probes can be automatically and reproducibly fabricated, and they simultaneously show high sensitivity and good reproducibility in SERS detections. A detection limit lower than 10−8 M in aqueous solvent for thiram and methyl parathion (MP) is achieved, and the relative standard deviation (RSD) of the SERS peaks is less than 6%. In addition, benefiting from numerous hotspots provided by micro-coffee rings, this micro-coffee-ring-patterned fiber SERS probe presents superior performance in in-situ trace detection of target molecules in complex liquid environments. Detection sensitivities of 10−7 M for thiram in lake water and in orange juice and 10−6 M for melamine and tetracycline in liquid milk are achieved. [ABSTRACT FROM AUTHOR]