Determination of Acetamiprid Residues in Vegetables by Indirect Competitive Chemiluminescence Enzyme Immunoassay

A sensitive chalcogenide-based electrochemical sensor for ultra-level detection of Mospilan residues in real samples

Addressed herein, the synthetic bismuthinite and bismuthinite@copper sulphide as two metal chalcogenides have been applied for modifying a glassy carbon electrode(GCE). The as-prepared nanomaterials were characterized using X-ray diffraction (XRD), scanning electron microscopy(SEM) and Energy-dispersive X-ray spectroscopy(EDX). By comparing the results, bismuthinite @copper sulphide hybridized with graphene oxide (GO) modified electrode exhibited superior sensitivity for detection ultra-levels of pesticide Mospilan (acetamiprid) in real samples. The dynamic concentration range of acetamiprid was found to be 80-680nM with a remarkably low detection limit about 4.1nM along with good stability and repeatability. Finally, the fabricated electrochemical sensor, bismuthinite@copper sulphide/GO, was suggested as a suitable alternative to more complex enzyme-based and aptamer-based methods for Mospilan detection.

A pretreatment-free and eco-friendly rapid detection for mycotoxins in edible oils based on magnetic separation technique

Pretreatment steps of current rapid detection methods for mycotoxins in edible oils not only restrict detection efficiency, but also produce organic waste liquid to pollute environment. In this work, a pretreatment-free and eco-friendly rapid detection method for edible oil is established. This proposed method does not require pretreatment operation, and automated quantitative detection could be achieved by directly adding oil samples. According to polarity of target molecules, the content of surfactant in reaction solutions could be adjusted to achieve the quantitative detection of AFB1 in peanut oil and ZEN in corn oil. The recoveries are between 96.5%-110.7% with standard deviation <10.4%, and the limit of detection is 0.17 μg/kg for AFB1 and 4.91 μg/kg for ZEN. This method realizes full automation of the whole chain detection, i.e. sample in-result out, and is suitable for the on-site detection of batches of edible oils samples.

Comprehensive analysis of neonicotinoids in Chinese commercial honey and pollen: A corresponding health risk assessment for non-targeted organisms

Neonicotinoids are broad-spectrum and highly effective insecticides that work by affecting neural activity in insects. Neonicotinoids are systemic pesticides that are absorbed by plants, transported, and accumulated in plant tissues, including nectar and pollen. Currently, there is a lack of a comprehensive assessment of the level of neonicotinoid contamination and the associated health risks to non-targeted organisms in commercial honey and pollen produced in China. This study collected 160 batches of honey and 26 batches of pollen from different regions and plant sources in China, analyzed the residue patterns of neonicotinoid pesticides, and comprehensively evaluated the exposure risks to non-targeted organisms including bees (adults and larvae) and humans. Furthermore, this study addresses this imperative by establishing a high-throughput, rapid, and ultra-sensitive indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on broad-spectrum monoclonal antibodies to detect and quantify neonicotinoids, with validation conducted using the LC-MS/MS method. The findings indicated that 59.4 % of honey samples contained at least one of eight neonicotinoids, and the ic-ELISA rapid detection and calculation method could detect all the samples containing neonicotinoids. Additionally, the dietary risk assessment for humans and honeybees indicates that the consumption of a specific quantity of honey may not pose a health risk to human due to neonicotinoid intake. However, the Risk Quotient values for imidacloprid to adult bees and bee larvae, as well as clothianidin to bee larvae, were determined to be 2.22, 5.03, and 1.01, respectively-each exceeding 1. This highlights the elevated risk of acute toxicity posed by imidacloprid and clothianidin residues to honey bees. The study bears significant implications for the safety evaluation of non-targeted organisms in the natural food chain. Moreover, it provides scientific guidance for protecting the diversity and health of the ecosystem.

Carbon dots-based fluorescent probe for the detection of imidacloprid residue in leafy vegetables

Consumption of leafy vegetables with excessive imidacloprid (IMI) can cause serious harm to the human body. To achieve rapid IMI detection, a carbon dots (CDs)-based fluorescent (FL) probe was hydrothermally prepared using O-phenylenediamine as the precursor. The morphology, particle size distribution, crystal structure, optics and chemical bond state of the as-prepared CDs were characterized. The mechanism of the CDs in detecting IMI was investigated by Fourier transform infrared spectroscopy, and the CDs' selectivity, stability, sensitivity, and actual sample recovery were tested. The CDs showed good selectivity, stability, and anti-interference ability. Under optimum conditions, there was a strong linear relationship between the FL intensity of the CDs and the IMI concentration in the range of 0.037-0.2 mg/L. The detection limit was 0.00187 mg/kg. The CDs were successfully applied to detect IMI in lettuce, cole, spinach, and pakchoi with spiked recoveries between 81.026% and 106.803% and a relative standard deviation between 0.001 and 0.027%.

Application of Immunoassay Technology in Food Inspection

Food safety is as important as ever, and the safeguards implemented to inspect and reduce pesticides, veterinary drugs, toxins, pathogens, illegal additives, and other deleterious contaminants in our food supply has helped improve human health and increase the length and quality of our lives [...].

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.

Broad-specificity monoclonal antibody against neonicotinoid insecticides via a multi-immunogen strategy and development of a highly sensitive GNP-based multi-residue immunoassay in ginseng and tomato

Neonicotinoid insecticides (NNIs) are extensively used across the agricultural products and foods. In order to meet the rapid detection requirements, a novel broad-specificity monoclonal antibody against NNIs was developed for the first time using a multi-immunogen strategy. The antibody's high affinity and its ability to bind target molecules were verified by ic-ELISA. Furthermore, molecular docking was used to evaluate the pivotal forces affecting binding affinity and to determine binding sites. Subsequently, a highly sensitive gold nanoparticle-based immunochromatographic assay was established for the rapid detection of eight NNIs and the IC₅₀ values were 0.03-1.61 ng/mL. The limits of detection for ginseng and tomato ranged from 0.76 to 30.19 μg/kg and 0.87 to 31.57 μg/kg, respectively. The spiked recovery ranged from 72.04% to 120.74%, and the coefficient of variation were less than 9.0%. This study provides a new direction for the development of multiple NNIs residue immunoassays.