FOOD CHEMISTRY
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2022
·
IF 9.231
Xinai Zhang,Yue Zhou,Xueyue Huang,Xuetao Hu,Xiaowei Huang,Limei Yin,Qilin Huang,Yunbo Wen,Bin Li,Jiyong Shi,Xiaobo Zou
Persistent usage of pesticides in agriculture has posed serious damage to overall ecosystem and human health, and thereby it is imperative to develop sensitive and efficient tools to evaluate residual pesticides in food and environmental setting. Herein, we reported a switchable colorimetric probe toward fipronil residue sensitized with aptamer-fueled catalytic activity of affiliative ZIF-8. Innovatively, it was found that the attached aptamer preferred to adsorb 3,3′,5,5′-tetramethylbenzidine (TMB) rather than 2,2-azinobis (3-ethylbenzothiazo-line-6-sulfonic acid) (ABTS), greatly promoting catalytic oxidation of ZIF-8 toward TMB for further improving sensitivity. Aiding with smartphone-based image acquisition, fipronil-responsive discoloration degree was converted into the ratio of green and blue (G/B) with limit of detection as low as 0.036 μM (0.016 μg·g −1 ). Moreover, it allowed for fipronil analysis in water, soil and vegetable samples with good recovery between 87 % and 110 %, verifying extension application prospect of the aptamer-fueled colorimetry for on-field pesticide evaluation in food safety supervision.
研究领域:
食品安全
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环境科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PEST MANAGEMENT SCIENCE
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2023
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IF 4.1
Xiaomu Qiao,Tianhao Zhou,Jing Zhang,Lixin Zhang,Yaobin Lu,Jia Huang
BACKGROUND Insect RDL (resistant to dieldrin) receptors are essential pentameric ligand-gated chloride channels that mediate the neuroinhibitory effect of GABA, the chief inhibitory neurotransmitter in the central nervous system. These receptors serve as primary targets for various insecticides, including noncompetitive antagonists (NCAs) such as cyclodiene organochlorines and phenylpyrazoles, as well as allosteric modulators like meta-diamides and isoxazolines. This study focuses on a newly discovered A2′N mutation within the RDL receptors, identified in fipronil-resistant planthoppers. Despite in vitro electrophysiological studies have proposed its role in conferring target-site resistance, in vivo genetic functional validation of this mutation remains unexplored. RESULTS Our research employed toxicity bioassays, assessing various Rdl genotypes against a spectrum of insecticides, including fipronil, α-endosulfan, broflanilide, and isocycloseram. Results revealed distinct resistance profiles for A2′N and A2′S mutants, indicating different binding interactions of RDL receptors with NCAs. Significantly, the A2′N heterozygote showed substantial resistance to fipronil, despite its homozygous lethality. Molecular modeling and docking simulations further supported these findings, highlighting unique binding poses for fipronil and α-endosulfan. CONCLUSION This study confirmed that A2′N mutation of the RDL GABA receptor confer high resistance to fipronil in vivo . The observed resistance in A2′N mutants is likely attributable to a steric hindrance mechanism, wherein the introduction of larger side chains hampers fipronil binding, even in a heterozygous state. © 2023 Society of Chemical Industry.
研究领域:
昆虫学
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神经生物学
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毒理学
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产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2023
·Vol. 15
·期 35
·4494-4505
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IF 3.1
Chao Sun,Lizheng Wang,Naiyu Guo,Runze Hu,Li Ye,Zhiming Hu,Jianjun Ding
Surface-enhanced Raman scattering (SERS) has a unique fingerprint spectrum, which allows for rapid, highly sensitive, and non-destructive detection without the need for sample pretreatment. However, SERS substrates have disadvantages such as short storage time and poor reproducibility. In this study, carbon nanotubes, gold, and silver were combined to take advantage of their inherent structural and characteristic properties that enhance the Raman effect. A new type of SERS composite substrate, CNTs/Ag@Au/SiO2, was prepared using a hydrothermal method and seed growth method. The substrate was characterized using transmission electron microscopy (TEM), and the average distance between the core–shell nanoparticles was found to be 3.1 nm, which is more suitable than other gold–silver combined core–shell structures and significantly improves the SERS enhancement factor. The substrate demonstrated high sensitivity even at low concentrations of probe molecules and good uniformity at five randomly selected locations. After storage for 45 days, the substrate still exhibited good stability. In most gold–silver combined core–shell structures, the detection limit for Rhodamine 6G (R6G) is 10−9 mol L−1, while in this substrate, the detection limit for R6G is 10−11 mol L−1. Furthermore, the contribution of the substrate's enhancement was deeply investigated using finite-difference time-domain (FDTD), which revealed that the substrate's hotspots were present in two forms: the “hotspots generated between Ag@Au nanoparticles” and the “hotspots generated between Ag@Au nanoparticles and carbon nanotubes”. These two forms of hotspots also demonstrated that the performance brought about by the preparation of the substrate structure was reliable. The simulation results were compared with the experimental results, and the analysis showed that the real environment would have an impact on the substrate's structure during the actual substrate preparation process. Finally, the substrate was used for detecting the pesticide fipronil, and the results showed clear peaks even at a concentration of 0.1 mg L−1. The results indicated that the Raman intensity was linearly exponential with the fipronil solution concentration, with a determination coefficient of R2 = 0.991. This study provides a new SERS substrate for pesticide residue detection and further explores the improvement of pesticide detection limits.
研究领域:
分析化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
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2019
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IF 4.916
Muhammad Muhammad,Guohua Yao,Jie Zhong,Kuanglin Chao,Muhammad Hammad Aziz,Qing Huang
Fipronil is a phenylpyrazole insecticide commonly used in agriculture and residential applications. In this paper, we reported a novel label-free surface-enhanced Raman spectroscopy (SERS) method for detection of fipronil residues in chicken eggs (mostly accumulated on the egg membrane). We fabricated the SERS substrates composed of the SiO 2 @Au core/shell nanoparticles and probed the contamination of fipronil residue on the egg membrane. The identification of the characteristic Raman bands of fipronil was achieved with the aid of density functional theory (DFT) calculation, with which we could analyzed the trace amount of fipronil in a quantitative way. As such, this work may provide a practical solution to quick inspection of fipronil contamination in chicken eggs or other foods.
研究领域:
食品安全检测
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分析化学
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环境科学
✓ 已验证
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2019
·
IF 4.527
Zhiwei Wang,Junhui Chen,Tianrong Zhan,Xiuping He,Baodong Wang
Neonicotinoids (NEOs) and fipronil (FIP) are insecticides that are widely used in modern agriculture and have received considerable attention in recent years due to their adverse effects on non-target organisms in the environment. In the present study, a new method to simultaneously detect eight common NEO insecticides and FIP and its three transformation products (FIPs) in sediments was developed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) based on a combined pretreatment of continuous solvent extraction (CSE) and solid phase extraction (SPE). Under optimized conditions, 5.0 g of freeze-dried sediment samples were initially extracted with methanol (20 mL)–methanol (15 mL)–water (20 mL) in sequence, and then the extract was cleaned with hydrophilic–lypophilic balance SPE cartridges, and HPLC-MS/MS analysis was conducted. The established method was validated to be sensitive, linear, accurate, and precise. The limits of detection (LOD) and limits of quantification (LOQ) of target compounds were 0.012–0.055 μg/kg d.w and 0.031–0.091 μg/kg d.w, respectively. Good linearity ( R 2 > 0.990) was observed between 4.0 × 10 −2 and 20.0 μg/kg d.w. The recovery rates of all target insecticides were between 75.5% and 98.5%, and the relative standard deviations (RSD) were all less than 15.0% at the low, medium, and high spiked levels. Finally, the optimized method was applied to analyze 12 target insecticides in the sediments obtained from Jiaozhou Bay of China and its main inflow rivers. Acetamiprid, thiamethoxam , fipronil sulfide, and fipronil sulfone were detected in the river sediment samples at the concentration from
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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