Bao-Zhu Jia

Aldicarb is a highly toxic carbamate insecticide strictly regulated in vegetables, yet sensitive immunoassays remain limited because its small size and simple structure hinder the generation of high-performance antibodies. Two aldicarb haptens, Ald-262 and Ald-296, carrying an extended alkyl spacer and a benzene-containing spacer, respectively, at the carbamate terminus, were designed and synthesized by a total-synthesis route and characterized by mass spectrometry and density functional theory, which verified that the spacers preserve the epitope. Screening of homologous and heterologous hapten–carrier pairings showed that Ald-262 as an immunogen with Ald-296 as a coating antigen gave the best ic-ELISA response (IC₅₀ = 11.94 ng/mL). Based on this antibody, a colloidal gold-based LFIA was developed, providing a detection range of 18.9–360.7 ng/mL, an IC₅₀ of 82.5 ng/mL, and an estimate of the limit of detection (IC₁₀) of 8.0 ng/mL. In spiked tomato and lettuce, it gave recoveries of 80.1–110.7% with coefficients of variation below 13.0% and correlated closely with UHPLC-MS/MS (y = 0.983x, R² = 0.983). These findings demonstrate that rational modulation of hapten spacer architecture provides an effective strategy for antibody generation against structurally simple small-molecule pesticides and enables rapid on-site screening of aldicarb residues in vegetables.

Fishery anesthetics are extensively employed in aquaculture to mitigate stress and reduce mortality during handling, transportation, and processing of farmed fish. While they enhance operational efficiency and reduce economic losses for fish merchants, the potential residual presence of these anesthetics raises concerns regarding human health risks and environmental impact. This review examines six commonly used anesthetics in aquaculture—eugenol, MS-222, benzocaine, 2-phenoxyethanol, diazepam, and quinaldine—focusing on their mechanisms of action, application risks, ecotoxicological effects, and methods for residue analysis. The objective is to promote the safe and informed application of these anesthetics, mitigate their biological toxicity, and minimize their ecological impact. Furthermore, the review provides technical insights into monitoring and managing anesthetic residues in aquaculture to ensure the safety of aquatic products and safeguard environmental health while also supporting the development of sustainable aquaculture practices.

Butralin (BL) is a dinitroaniline herbicide commonly applied in agriculture to control annual grasses and broadleaf weeds. However, its environmental persistence and potential toxicity to nontarget organisms, including aquatic species and humans, have raised serious concerns. Reliable monitoring of BL residues is therefore crucial for ensuring environmental and food safety. In this study, a novel hapten was synthesized by introducing an ethylenediamine group at the C1 position of 4-tert-butyl-2,6-dinitrobenzene, followed by spacer arm extension via succinic anhydride acylation. Using this hapten, a specific monoclonal antibody (mAb) against BL was generated, exhibiting the highest affinity reported to date. Based on this mAb, an optimized indirect competitive ELISA (ic-ELISA) was established, providing excellent sensitivity with an IC₅₀ of 0.385 ng/mL and a linear detection range (IC₂₀-IC₈₀) of 0.012-1.24 ng/mL. The mAb also demonstrated remarkable specificity for BL, with negligible cross-reactivity toward structurally related analogs, confirming its potential for developing sensitive and selective immunoassays for residue monitoring in environmental and food samples.

Fishery anesthetics are extensively employed in aquaculture to mitigate stress and reduce mortality during handling, transportation, and processing of fish. While they enhance operational efficiency and reduce economic losses for fish merchants, the potential residual presence of these anesthetics raises concerns regarding human health risks and environmental impact. This review examines six commonly used anesthetics in aquaculture—eugenol, MS-222, benzocaine, 2-phenoxyethanol, diazepam, and quinaldine—focusing on their mechanisms of action, application risks, ecotoxicological effects, and methods for residue analysis. The objective is to promote the safe and informed application of these anesthetics, mitigate their biological toxicity, and minimize their ecological impact. Furthermore, the review provides technical insights into monitoring and managing anesthetic residues in aquaculture to ensure the safety of aquatic products and safeguard environmental health, while also supporting the development of sustainable aquaculture practices.

Hydrocortisone is a typical glucocorticoid commonly used in livestock production; however, its overuse can result in hormone residues in milk. Long-term consumption of such milk may lead to a series of health issues. Therefore, the timely and rapid detection of hydrocortisone in milk is crucial for protecting human health. In this study, a magnetic particle-based direct chemiluminescence immunoassay (MP-DCLIA) incorporating a streptavidin–biotin signal amplification system was developed for the rapid and high-throughput detection of hydrocortisone in milk. Automated operations reduce human error and enhance the accuracy and repeatability of tests. The assay can be completed in 12 min with a linear detection range of 13.09–261.71 μg/L, a limit of detection (LOD) of 4.94 μg/L, a limit of quantification (LOQ) of 14.84 μg/L, and intra- and inter-batch variations of less than 5%. The method demonstrated stability and exhibited no cross-reactivity with structural analogues. Spiked recoveries of milk samples ranged from 85.85% to 100.30%, with results strongly correlating with those obtained from LC-MS/MS. The MP-DCLIA offers rapidity, high efficiency, stability, and precision, making it a promising tool for practical testing applications.

Aflatoxin B₁ (AFB₁) is highly toxic and difficult to prevent. It is mainly produced by fungi and exists in plants and animals and is classified by the World Health Organization as a class I carcinogen, posing a serious threat to human and animal health. Therefore, it is important to establish an efficient, sensitive, and on-site detection method for AFB₁ to protect human health. The immunochromatographic test strip method is simple, sensitive, and can achieve real-time detection. However, traditional immunochromatographic test strips have low sensitivity due to their relatively weak optical properties. In this study, Nb-G8 was biotinylated using a chemical method. Two sizes of gold nanoflowers (AuNFs) were prepared and combined with biotinylated G8 and streptavidin to form two types of probes. These probes were sprayed on gold standard pads and expanded pads, respectively, to enhance the signals through the high affinity interaction between streptavidin and biotin. Under the optimal experimental conditions, the half maximal inhibitory concentration (IC₅₀) of this method was 5.0 ng/mL and the limit of detection (IC₁₀) was 0.03 ng/mL, which increased the sensitivity of the test strip by four-fold compared with that of the traditional biotinylated nanoantibody immunochromatography test strip and had a wider detection range. In conclusion, the use of a high-affinity amplification signal between biotin and streptavidin is a valuable method for the detection of aflatoxin.