The Experts below are selected from a list of 2532 Experts worldwide ranked by ideXlab platform
Minghua Wang - One of the best experts on this subject based on the ideXlab platform.
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A fluorescence polarization immunoassay for detection of Thiacloprid in environmental and agricultural samples
RSC Advances, 2020Co-Authors: Yuan Ding, He Chen, Qian Yang, Lu Feng, Minghua WangAbstract:As a widely used neonicotinoid insecticide, Thiacloprid has been observed to pose a risk to honeybees and the endocrine system of mammals. So a detection method with high sensitivity, simple operation and high throughput is required. Based on this consideration, we prepared an anti-Thiacloprid monoclonal antibody (mAb, C9) and developed a fluorescence polarization immunoassay (FPIA) for the detection of Thiacloprid. After optimizing the length of spacer and reaction conditions, the 50% inhibition concentration (IC50), limit of detection (LOD) and linear range (IC20 ∼ IC80) of the FPIA are 15.34 ng mL−1, 2.43 ng mL−1 and 3.10–65.7 ng mL−1, respectively. Meanwhile, FPIA just requires 12 min to detect the pesticide with simple operation. Then the FPIA was used to detect the Thiacloprid in spiked rice, soil, cucumber and tomato samples, and recoveries were in the range of 79.1%–105.3% with 3.7%–12.3% standard deviation. The FPIA also shows good correlation with high-performance liquid chromatography for the detection of Thiacloprid in tomato samples.
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Competitive immunoassay for simultaneous detection of imidacloprid and Thiacloprid by upconversion nanoparticles and magnetic nanoparticles.
Environmental Science and Pollution Research, 2019Co-Authors: Jiaqi Deng, Yan Wang, He Chen, Yuan Ding, Minghua WangAbstract:A rapid and sensitive immunoassay for the simultaneous detection of imidacloprid and Thiacloprid was developed by using magnetic nanoparticles (MNPs) and upconversion nanoparticles (UCNPs). The UCNPs of NaYF4:Yb, Er and NaYF4:Yb, Tm were synthesized and conjugated with anti-imidacloprid monoclonal antibody (mAb) and anti-Thiacloprid mAb as signal labels, while the MNPs were conjugated with antigens of Thiacloprid and imidacloprid as separation elements. The fluorescence intensities of Yb/Er- and Yb/Tm-doped UCNPs were detected simultaneously in 544 nm and 477 nm under the excitation of NIR light (980 nm). The amounts of mAb-conjugated UCNPs that were separated by antigen-conjugated MNPs were determined based on competitive immunoassays. Under the optimal conditions, the 50% inhibiting concentration (IC50) and limit of detection (LOD, IC10) were 5.80 and 0.32 ng/mL for imidacloprid and 6.45 and 0.61 ng/mL for Thiacloprid, respectively. The immunoassay exhibited negligible cross-reactivity with analogs of imidacloprid and Thiacloprid except imidaclothiz (86.2%). The average recoveries of imidacloprid and Thiacloprid in environmental and agricultural samples, including paddy water, soil, pears, oranges, cucumbers, and wheat, ranged from 78.4 to 105.9% with relative standard deviations (RSDs) of 2.1–11.9% for imidacloprid and ranged from 82.5 to 102.3% with RSDs of 1.0–16.5% for Thiacloprid. In addition, the results of the immunoassay correlated well with high-performance liquid chromatography for the detection of the authentic samples.
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Development of an enzyme-linked immunosorbent assay for Thiacloprid in soil and agro-products with phage-displayed peptide
Analytical Biochemistry, 2015Co-Authors: Wei Yin, Xiude Hua, Haiyan Shi, Shirley J. Gee, Xiaofeng Liu, Minghua Wang, Bruce D. HammockAbstract:A monoclonal antibody (3A5) that can recognize Thiacloprid was produced, and a linear 8-residue peptide phage library was constructed. Six phage-displayed peptides were isolated from the linear 8-residue peptide phage library and a cyclic 8-residue peptide phage library. A phage enzyme-linked immunosorbent assay (ELISA) was developed to detect Thiacloprid using a phage-displayed peptide. Under the optimal conditions, the half-maximal inhibition concentration (IC50) and the limit of detection (IC10) of the developed phage ELISA were 8.3 and 0.7 μg/L, respectively. Compared with the conventional ELISA, the sensitivity was improved more than 3-fold. The cross-reactivity (CR) was less than 0.08% for the tested structural analogues and was regarded as negligible. The recoveries of Thiacloprid ranged from 80.3% to 116.3% in environmental and agricultural samples, which conformed to the requirements for residue detection. The amount of Thiacloprid detected by phage ELISA in the samples was significantly correlated with that detected by high-performance liquid chromatography. The current study indicates that isolating phage-displayed peptides from phage display libraries is an alternative method for the development of a sensitive immunoassay and that the developed assay is a potentially useful tool for detecting Thiacloprid in environmental and agricultural samples.
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quantum dots based fluoroimmunoassay for the simultaneous detection of clothianidin and Thiacloprid in environmental and agricultural samples
RSC Advances, 2015Co-Authors: Ming Li, Qiuxia Wang, Minghua WangAbstract:Quantum dots (QDs), luminescent semiconductor nanocrystals, have the potential to simplify the performance of multi-analyte analysis. In this work, a novel indirect competitive fluorescence-linked immunosorbent assay (FLISA) based on QDs for the detection of clothianidin and Thiacloprid simultaneously in environmental and agricultural samples were performed in a single well of the microtiter plate. The QDs-labeled antibody conjugates, which consists of CdSe/ZnS core–shell QDs and polyclonal antibodies, were prepared through the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) coupling method. Under optimal conditions, the half-maximal inhibition concentration (IC50) and the limit of detection (LOD, IC10) of the FLISA were 12.5 and 0.3 ng mL−1 for clothianidin, and 9.27 and 0.4 ng mL−1 for Thiacloprid, respectively. The cross-reactivities of the FLISA with the analogues of clothianidin and Thiacloprid were negligible except for dinotefuran (10.4% for clothianidin). The spiked recoveries were 73.3% to 113.1% with relative standard deviations (RSDs) of 2.7 to 13.3% for the detection of clothianidin and Thiacloprid in river water, soil, cabbage, rice and tomato. Furthermore, the results of FLISA for the authentic samples correlated well with those obtained by HPLC. The proposed FLISA is a satisfactory tool for rapid, sensitive, and quantitative detection of two pesticides simultaneously in agricultural and environmental samples. This study provides a strategy for the development of QDs-based fluoroimmunoassay for the quantitative analysis of two pesticides.
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development of a chemiluminescence enzyme linked immunosorbent assay for the simultaneous detection of imidaclothiz and Thiacloprid in agricultural samples
Analyst, 2013Co-Authors: Xiuying Xu, Minghua WangAbstract:A novel and sensitive enhanced chemiluminescence enzyme-linked immunosorbent assay (ECL-ELISA) for the simultaneous analysis of imidaclothiz and Thiacloprid is described. The concentrations of coating antibodies and enzyme tracers were optimised by three different ECL-ELISA formats. Under the optimised conditions, when anti-imidaclothiz polyclonal and anti-Thiacloprid polyclonal antibodies were immobilised in a single well, single-enzyme tracer ECL-ELISA was used to screen the corresponding pesticide residue, and multi-enzyme tracer ECL-ELISA was used for the analysis of imidaclothiz and Thiacloprid residue mixtures. The average recoveries of the two pesticides from spiked tomato, cabbage, and rice samples were in the range of 83.7–117%. Meanwhile, the results showed that the multi-enzyme tracer ECL-ELISA could be applied to the accurate analysis of different proportions of imidaclothiz and Thiacloprid (1:4 to 4:1, m/m) when the gross residues ranged from 20 to 250 μg kg−1. The results of the multi-enzyme tracer ECL-ELISA in the real tomato samples correlated well with those of high-performance liquid chromatography, with a correlation coefficient of 0.996. Therefore, this new strategy for developing immunoassays is suitable for the simultaneous quantitative detection of imidaclothiz and Thiacloprid residues in agricultural samples.
Alessandro Feis - One of the best experts on this subject based on the ideXlab platform.
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surface enhanced raman spectra of the neonicotinoid pesticide Thiacloprid
Journal of Raman Spectroscopy, 2013Co-Authors: Maria Vega Canamares, Alessandro FeisAbstract:Thiacloprid is a widely used pesticide belonging to the neonicotinoid class, which is characterized by a selective activity against insects and a reduced acute toxicity for humans. The importance of the environmental impact of neonicotinoids is being intensively researched, in order to evaluate the danger they pose for useful insects. Physical methods which allow the characterization ofneonicotinoidsindilutedaqueoussolutionsare thereforedesirable.Wepresent astudyofRamanandsurface-enhancedRaman scattering (SERS) spectroscopy on Thiacloprid in solid state, in acetone solution, and adsorbed onto silver and gold hydrosols at mM concentration. Density functional theory calculations allow the individualization of the most stable molecular structure, both ingasphaseandinsolution,andofthecorrespondingRamanspectra.Thevibrationalassignmentsleadtoaninterpretationofthe differences between SERS and ordinary Raman spectra based on the possible interactions between the molecule and the metal surface, the main one involving the iminocyano group. Formation of a charge-transfer complex is suggested by the dependence oftheSERSspectraonthelaserexcitationwavelength.WeevaluatetheapplicabilityofSERSspectroscopytothechemicalanalysis of Thiacloprid comparing SERS with current analytical methods. Copyright © 2013 John Wiley & Sons, Ltd. Supporting information may be found in the online version of this article.
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Surface‐enhanced Raman spectra of the neonicotinoid pesticide Thiacloprid
Journal of Raman Spectroscopy, 2013Co-Authors: Maria Vega Canamares, Alessandro FeisAbstract:Thiacloprid is a widely used pesticide belonging to the neonicotinoid class, which is characterized by a selective activity against insects and a reduced acute toxicity for humans. The importance of the environmental impact of neonicotinoids is being intensively researched, in order to evaluate the danger they pose for useful insects. Physical methods which allow the characterization ofneonicotinoidsindilutedaqueoussolutionsare thereforedesirable.Wepresent astudyofRamanandsurface-enhancedRaman scattering (SERS) spectroscopy on Thiacloprid in solid state, in acetone solution, and adsorbed onto silver and gold hydrosols at mM concentration. Density functional theory calculations allow the individualization of the most stable molecular structure, both ingasphaseandinsolution,andofthecorrespondingRamanspectra.Thevibrationalassignmentsleadtoaninterpretationofthe differences between SERS and ordinary Raman spectra based on the possible interactions between the molecule and the metal surface, the main one involving the iminocyano group. Formation of a charge-transfer complex is suggested by the dependence oftheSERSspectraonthelaserexcitationwavelength.WeevaluatetheapplicabilityofSERSspectroscopytothechemicalanalysis of Thiacloprid comparing SERS with current analytical methods. Copyright © 2013 John Wiley & Sons, Ltd. Supporting information may be found in the online version of this article.
A Abd M Elaty - One of the best experts on this subject based on the ideXlab platform.
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liquid chromatography tandem mass spectrometry quantification of acetamiprid and Thiacloprid residues in butterbur grown under regulated conditions
Journal of Chromatography B, 2017Co-Authors: A Abd M Elaty, Hyung Suk Chung, Md Humayun Kabir, Md Musfiqur Rahman, Ji Hoon Jeong, Byungjoon Chang, Hochul Shin, Jaehan ShimAbstract:Abstract An analytical method was developed to quantify the residual levels of the neonicotinoid insecticides, acetamiprid and Thiacloprid, in field-incurred butterbur samples using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Samples were extracted with acetonitrile and partitioned with dichloromethane. After partitioning, purification was conducted using a Florisil ® cartridge. Linearity of a matrix-matched calibration curve of the two compounds over a concentration range of 0.004–0.4 μg/g was excellent, with determination coefficients ( R 2 ) ≥ 0.9998. The limits of detection (LOD) and quantitation (LOQ) for both acetamiprid and Thiacloprid were 0.0006 and 0.002 mg/kg, respectively. The average recoveries for acetamiprid and Thiacloprid at two spiking levels (0.02 and 0.1 mg/kg, i.e. , 10 × LOQ and 50 × LOQ) were between 78.23 to 82.17%, with relative standard deviations (RSDs) ≤ 7.22%. The method was successfully applied to field-incurred samples treated with a commercial pesticide product, either once (zero or 7 days before harvest) or twice (0 and 7, 7 and 14, or 14 and 21 days before harvest). The highest and lowest residues were obtained for the 7 and 0 days’ treatment and the 21 and 14 days’ treatment, respectively. The developed method is simple and accurate and can be extrapolated to other leafy vegetables.
Ming Li - One of the best experts on this subject based on the ideXlab platform.
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sensitive detection of Thiacloprid in environmental and food samples by enhanced chemiluminescent enzyme immunoassay
RSC Advances, 2016Co-Authors: Hai Xu, Ming Li, Zhen Zhang, Guan D Zhao, Dao L DuAbstract:A fast and sensitive enhanced chemiluminescent enzyme immunoassay (ECL-EIA) was developed based on horseradish peroxidase detected with a luminol-based substrate for neonicotinoid insecticide Thiacloprid in environmental and food samples. Toward this goal, a variety conditions of chemiluminescent substrate solution including the reacting buffer, the concentrations of p-iodophenol, luminol and H2O2 were optimized. Under the optimal conditions, the sensitivity (the 50% inhibitory concentration value) was 1.80 ng mL−1. The ECL-EIA was 5.5 times more sensitive compared to the colorimetric-EIA. The average recoveries of Thiacloprid from ten spiked samples were estimated to range from 79.7 to 119%, with relative standard deviations of 4.2 to 11.2%. The dissipation of Thiacloprid applied to real tomato samples was monitored with the ECL-EIA and HPLC methods. The ECL-EIA results agreed well with the HPLC results (R2 = 0.993). These results suggested that the Thiacloprid in the samples could be simply, rapidly and accurately detected by ECL-EIA.
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quantum dots based fluoroimmunoassay for the simultaneous detection of clothianidin and Thiacloprid in environmental and agricultural samples
RSC Advances, 2015Co-Authors: Ming Li, Qiuxia Wang, Minghua WangAbstract:Quantum dots (QDs), luminescent semiconductor nanocrystals, have the potential to simplify the performance of multi-analyte analysis. In this work, a novel indirect competitive fluorescence-linked immunosorbent assay (FLISA) based on QDs for the detection of clothianidin and Thiacloprid simultaneously in environmental and agricultural samples were performed in a single well of the microtiter plate. The QDs-labeled antibody conjugates, which consists of CdSe/ZnS core–shell QDs and polyclonal antibodies, were prepared through the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) coupling method. Under optimal conditions, the half-maximal inhibition concentration (IC50) and the limit of detection (LOD, IC10) of the FLISA were 12.5 and 0.3 ng mL−1 for clothianidin, and 9.27 and 0.4 ng mL−1 for Thiacloprid, respectively. The cross-reactivities of the FLISA with the analogues of clothianidin and Thiacloprid were negligible except for dinotefuran (10.4% for clothianidin). The spiked recoveries were 73.3% to 113.1% with relative standard deviations (RSDs) of 2.7 to 13.3% for the detection of clothianidin and Thiacloprid in river water, soil, cabbage, rice and tomato. Furthermore, the results of FLISA for the authentic samples correlated well with those obtained by HPLC. The proposed FLISA is a satisfactory tool for rapid, sensitive, and quantitative detection of two pesticides simultaneously in agricultural and environmental samples. This study provides a strategy for the development of QDs-based fluoroimmunoassay for the quantitative analysis of two pesticides.
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development and evaluation of an enzyme linked immunosorbent assay for the determination of Thiacloprid in agricultural samples
Food Analytical Methods, 2013Co-Authors: Ming Li, Minghua WangAbstract:An enzyme-linked immunosorbent assay (ELISA) was developed based on a polyclonal antibody for the analysis of Thiacloprid in agricultural samples. Thiacloprid hapten was synthesized and conjugated to bovine serum albumin to produce an immunogen and ovalbumin to produce a coating antigen. Polyclonal antibodies were obtained from immunized New Zealand white rabbits. Under optimal conditions (5 % methanol, 0.1 mol/L Na+, pH 5.5), the ELISA showed a 50 % inhibitory concentration (IC50) value of 0.01 mg/L and a limit of detection (IC10) of 0.47 μg/L. No obvious cross-reaction with the other structural analogs of neonicotinoid insecticides showed that the polyclonal antibodies had a high specificity for Thiacloprid. The average recoveries from spiked water, soil, pear, and tomato were in the range of 80 to 119 %. The results of the ELISA were confirmed by high-performance liquid chromatography, and the correlation of the results from the two methods had a high correlation coefficient of 0.99 (n = 3) in spiked samples (soil, pear, and tomato). The proposed ELISA could successfully be applied to the determination of Thiacloprid residues in agricultural samples.
Jaehan Shim - One of the best experts on this subject based on the ideXlab platform.
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liquid chromatography tandem mass spectrometry quantification of acetamiprid and Thiacloprid residues in butterbur grown under regulated conditions
Journal of Chromatography B, 2017Co-Authors: A Abd M Elaty, Hyung Suk Chung, Md Humayun Kabir, Md Musfiqur Rahman, Ji Hoon Jeong, Byungjoon Chang, Hochul Shin, Jaehan ShimAbstract:Abstract An analytical method was developed to quantify the residual levels of the neonicotinoid insecticides, acetamiprid and Thiacloprid, in field-incurred butterbur samples using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Samples were extracted with acetonitrile and partitioned with dichloromethane. After partitioning, purification was conducted using a Florisil ® cartridge. Linearity of a matrix-matched calibration curve of the two compounds over a concentration range of 0.004–0.4 μg/g was excellent, with determination coefficients ( R 2 ) ≥ 0.9998. The limits of detection (LOD) and quantitation (LOQ) for both acetamiprid and Thiacloprid were 0.0006 and 0.002 mg/kg, respectively. The average recoveries for acetamiprid and Thiacloprid at two spiking levels (0.02 and 0.1 mg/kg, i.e. , 10 × LOQ and 50 × LOQ) were between 78.23 to 82.17%, with relative standard deviations (RSDs) ≤ 7.22%. The method was successfully applied to field-incurred samples treated with a commercial pesticide product, either once (zero or 7 days before harvest) or twice (0 and 7, 7 and 14, or 14 and 21 days before harvest). The highest and lowest residues were obtained for the 7 and 0 days’ treatment and the 21 and 14 days’ treatment, respectively. The developed method is simple and accurate and can be extrapolated to other leafy vegetables.
