In situ and rapid determination of acetamiprid residue on cabbage leaf using surface-enhanced Raman scattering

Fabrication of versatile Fe3O4/GO/Au composite nanomaterial as SERS-active substrate for detection of pesticide residue

Highly active Fe3O4/GO/Au composite nanomaterial was fabricated as a substrate of surface-enhanced Raman spectroscopy (SERS) and applied for pesticide residue detection. The three-layer multifunctional Fe3O4/GO/Au nanoparticles (NPs) were designed by facile method, with high hotspots, and were characterized by various techniques, including ultraviolet spectrophotometry (UV), X-ray diffraction (XRD), infrared absorption spectrometer (IR), and transmission electron microscopy (TEM). The performance of Fe3O4/GO/Au was evaluated by Raman spectroscopy with R6G as a probe molecule to verify its enhancement effect. It exhibited a strong Raman signal with 10-6 M of R6G. Furthermore, the presence of Fe3O4/GO/Au nanohybrid enabled the SERS-based method to detect mancozeb and showed an excellent linear relationship in the range of 0.25-25 ppm, with a low limit of detection (0.077 ppm), satisfactory EF, stability, and repeatability. In addition, the mechanism of SERS enhancement with electromagnetic mechanism (EM) and chemical mechanism (CM) was discussed in detail. Therefore, the proposed SERS approach holds promise as an auxiliary technique for screening contaminated agricultural products, environmental sample, and food in the future.

Bupropion and varenicline administration reversed depressive behavior induced by acetamiprid exposure in mice: the role of nAChRs in depression

Acetamiprid (ACE), is a popular neonicotinoid pesticide, that has a high affinity for mammalian nicotinic acetylcholine receptors (nAChRs). Therefore, ACE might induce depressive effects by perturbing the cholinergic system in mammalian. The aim of this study was to evaluate the effects of ACE exposure on depressive-like behaviors and grip strength (GS) in mice. Also the possible role of nAChR activation in depression was assessed by varenicline, and bupropion. Male Swiss mice (27 ± 2 g) were daily exposed to ACE by gavage (0.1, 1, 5 mg/kg), behavioral tests took place after 3 h, 7 days and 15 days, the subacute ACE (0.1 mg/kg) exposure was assessed after 30 days. Varenicline (0.5 mg/kg) or bupropion (4 mg/kg) were injected intraperitoneally 30 min prior exposure to (1 mg/kg) ACE. The locomotor activity, forced swimming test (FST), and sucrose preference (SP) test were assessed. After a week ACE dose dependently increased the immobility time during FST, and after 15 days' depressive behavior was observed equally for ACE (0.1-5 mg/kg). The subacute exposure (0.1 mg/kg) significantly increased the immobility time, SP also declined that revealed anhedonia. These behavioral changes showed that ACE can initiate depressive effects. The changes in locomotor activity were not significant. GS significantly reduced following a week of exposure to ACE (1-5 mg/kg) that indicated neurotoxicity. These effects were antagonized by bupropion or varenicline, thus ACE effect on nAChRs was essential in initiating the depressive behavior.

Detection of neonicotinoids in agricultural products using magnetic molecularly imprinted polymers-surface enhanced Raman spectroscopy

In this paper, magnetic molecularly imprinted polymers-surface-enhanced Raman spectroscopy (MMIPs-SERS) for rapidly analyzing acetamiprid and thiacloprid in agricultural products has been firstly developed. The magnetic imprinted polymers were obtained by polymerizing the imprinted layers on the surface of magnetic nanoparticles. The polymers were detailed characterized by using series of analytical techniques, and their adsorption and recognition performance were validated by adsorption tests. The results showed that the magnetic molecularly imprinted polymers possessed typically core-shell structure and exhibited class-specific recognition, fast adsorption saturation (only 1 min), and good magnetic separation performance towards targets. The adsorption and desorption conditions for MMIPs-SERS detection system were carefully investigated. Under optimum conditions, the good linear detection range of 1∼20 μg/g with LODs of 23.7-68.8 ng/g for acetamiprid and thiacloprid in peach and pear samples was obtained. Through the reusable and spiked experiments, the developed MMIPs-SERS method based on Au NPs as enhanced substrate was validated to be highly sensitive, accurate, efficient and applicable in analyzing neonicotinoids from pear and peach samples. This study provided a rapid and simple detection method for neonicotinoids with effective separation and detection properties based on the synergistic effect of imprinted polymers and SERS. More importantly, this developed method have good application potential in rapid analyzing field for neonicotinoids due to the amazing rapid adsorption time for extracting targets from complex food matrix (only 1 min).

Biochar Derived from Pineapple Leaf Non-Fibrous Materials and Its Adsorption Capability for Pesticides

Non-fibrous materials (NFMs) are typically discarded during pineapple leaf fiber processing. The underutilized NFM waste was proposed for use in this work as a raw material for the production of biochar . The removal of pesticides (acetamiprid, imidacloprid, or methomyl) from water was then investigated using the NFM derived biochar (NFMBC). The pseudo-second-order kinetic data suggested chemisorption of pesticide on NFMBC. While acetamiprid or imidacloprid adsorption on NFMBC occurred primarily via multi-layered adsorption (best fitted with the Freundlich isotherms), the Sips adsorption isotherms matched with the experimental data, implying heterogeneous adsorption of methomyl on the biochar surface. The adsorption capacities for acetamiprid, methomyl, and imidacloprid are 82.18, 36.16, and 28.98 mg g^-1, respectively, which are in agreement with the order of the polarity (low to high) of pesticides. Adsorption capacities indicated that the NFMBC preferably removed low-polarity pesticides from water sources. Since pineapple leaves provide fibers and NFMs for materials development, this study should promote an extended agro-waste utilization approach and full-cycle resource management in pineapple fields.

In Silico Investigation of Selected Pesticides and Their Determination in Agricultural Products Using QuEChERS Methodology and HPLC-DAD

In this study, we considered some pesticides as active substances within formulations for the protection of plant-based food in the Republic of Serbia in silico, because these pesticides have not often been investigated in this way previously, and in an analytical way, because there are not very many available fast, cheap, and easy methods for their determination in real agricultural samples. Seven pesticides were detected in selected agricultural products (tomatoes, cucumbers, peppers, and grapes) using the QuEChERS methodology and HPLC-DAD. Standard curves for the investigated pesticides (chlorantraniliprole, methomyl, metalaxyl, thiacloprid, acetamiprid, emamectin benzoate, and cymoxanil) show good linearity, with R² values from 0.9785 to 0.9996. The HPLC-DAD method is fast, and these pesticides can be determined in real spiked samples in less than 15 min. We further characterized the pesticides we found in food based on physicochemical properties and molecular descriptors to predict the absorption, distribution, metabolism, elimination, and toxicity (ADMET) of the compounds. We summarized the data supporting their effects on humans using various computational tools to determine their potential adverse effects. The results of our prediction study show that all of the selected pesticides considered in this study have good oral bioavailability, and those with high toxicity, therefore, could be harmful to human health. Chlorantraniliprole was shown in a molecular docking study as a good starting point for a new Alzheimer's disease drug candidate.

Nondestructive testing methods for pesticide residue in food commodities: A review

Pesticides play an important role in increasing the overall yield and productivity of agricultural foods by controlling pests, insects, and numerous plant-related diseases. However, the overuse of pesticides has resulted in pesticide contamination of food products and water bodies, as well as disruption of ecological and environmental systems. Global health authorities have set limits for pesticide residues in individual food products to ensure the availability of safe foods in the supply system and to assist farmers in developing the best agronomic practices for crop production. Therefore, the use of nondestructive testing (NDT) methods for pesticide residue detection is gaining interest in the food supply chain. The NDT techniques have several advantages, such as simultaneous measurement of chemical and physical characteristics of food without destroying the product. Although numerous studies have been conducted on NDT for pesticide residue in agro-food products, there are still challenges in real-time implementation. Further study on NDT methods is needed to establish their potential for supplementing existing methods, identifying mixed pesticides, and performing volumetric quantification (not surface accumulation alone).

Real-time and in situ monitoring of organosilicon-induced thiram penetration into cabbage leaves by surface-enhanced Raman scattering mapping

BACKGROUND

Understanding pesticide penetration behavior is important for effective application of pesticides. However, there is a lack of an effective method to monitor pesticide penetration behavior and its changing process. In the present study, a novel surface-enhanced Raman scattering (SERS) mapping method was used for real-time and in situ tracking of the penetration behaviors of thiram and thiram-organosilicon mixture on cabbage leaves.

RESULTS

The results suggest that thiram has very weak ability to penetrate into cabbage leaves. However, when the thiram-organosilicon mixture was placed on leaf surfaces, a clear thiram signal was detected inside the leaf after 2 h of exposure, a strong signal was observed after 12 h, and the penetration depth of thiram was approximately 200 μm after 48 h.

CONCLUSION

SERS mapping was demonstrated to be a reliable method for in situ monitoring of organosilicon-induced thiram penetration into cabbage leaf over time. The present study provides a new reference for rationally selecting adjuvants, effectively applying pesticides, and reducing pesticides residue in food. © 2022 Society of Chemical Industry.

Irradiation-Induced Synthesis of Ag/ZnO Nanostructures as Surface-Enhanced Raman Scattering Sensors for Sensitive Detection of the Pesticide Acetamiprid

Detecting pesticides using techniques that involve simple fabrication methods and conducting the detection at very low levels are challenging. Herein, we report the detection of acetamiprid at the quadrillionth level using surface-enhanced Raman scattering (SERS). The SERS chip comprises Ag nanoparticles deposited on a tetrapod structure of ZnO coated onto indium tin oxide glass (denoted as Ag@ZnO-ITO). Controlled Ag decoration of ZnO occurs via irradiation-induced synthesis. The morphology of the surface plays a significant role in achieving an enhanced SERS performance for acetamiprid detection. 4,4'-Dipyridyl (DPY) is used to investigate synthesis conditions for the chip, leading to an optimal irradiation time of 60 min. Furthermore, the enhancement factor for acetamiprid on Ag@ZnO-ITO is higher than 107. These results demonstrate that SERS sensors have the potential for practical use in acetamiprid detection.

A Sensitive SERS Method for Determination of Pymetrozine in Apple and Cabbage Based on an Easily Prepared Substrate

Residual pesticides are one of the major food safety concerns around the world. There is a demand for simple and reliable methods to monitor pesticide residues in foods. In this study, a sensitive method for determination of pymetrozine in apple and cabbage samples using surface-enhanced Raman spectroscopy (SERS) based on decanethiol functionalized silver nanoparticles was established. The proposed method performed satisfactorily with the linear detection range of 0.01-1.00 mg/L and limit of detection (LOD) of 0.01 mg/L in methanol. In addition, it was successfully used to detect pymetrozine in apple and cabbage samples, the LOD was 0.02 and 0.03 mg/L, respectively, and the recoveries of spiked cabbage and apple ranged 70.40-104.00%, with relative standard deviations below 12.18% and 10.33% for intra-day and inter-day tests. Moreover, the results of the correlation test with real cabbage samples of liquid chromatography-tandem mass spectrometry showed that they were highly correlated (slope = 0.9895, R2 = 0.9953). This study provides a sensitive approach for detection of pymetrozine in apple and cabbage, which has great potential for determination of pymetrozine residues in food products.