Mycotoxins are secondary metabolites produced by fungi. Food is highly susceptible to fungal contamination, leading to the production of various mycotoxins, which pose significant threats to food safety and human health. Given the diversity of food types and the complexity of their matrices, direct detection of mycotoxins in food is often affected by matrix effects. Therefore, establishing rapid and sensitive detection methods to monitor and control mycotoxin levels in food is of great importance. Covalent organic frameworks (COFs) are a type of porous organic material characterized by their large specific surface area, excellent stability, adjustable pore size and ease of functionalization, making them superior adsorbent materials. In recent years, COFs have become a popular material in the research of mycotoxin detection. This article categorized the synthesis methods of COFs materials and reviewed their research progress in the field of mycotoxin detection, aiming to provide a reference for the application of covalent organic framework materials in mycotoxin detection research.

Objective To investigate the neurobehavioral effects of fumonisin and hydrolyzed fumonisin in zebrafish under sub-lethal concentrations (9-270 mg/L). Methods Using Danio rerio as test organism, their spontaneous swimming distance and speed, and their locomotor activity under light-dark stimulation, as well as their distribution in different color areas of the cross maze were recorded by a behavioral toxicity recorder, and the data were statistically analyzed. Results The spontaneous locomotor activity of Danio rerio was significantly decreased after exposure in high concentration of fumonisin (79 mg/L), with a decrease of 70% in total movement distance and average swimming speed. In contrast, after exposure in low concentration of hydrolyzed fumonisin (30 mg/L), the spontaneous locomotor activity was significantly enhanced, with an increase of 130% or more of respective indicators. Fumonisin at subacute concentrations did not significantly affect the light-dark response ability of Danio rerio, but the hydrolyzed form of fumonisin showed a promoting effect at low concentrations and an inhibitory effect at high concentrations. After exposure to fumonisin or its hydrolyzed form, the preference of Danio rerio for blue and their avoidance of yellow and green were both weakened. Conclusion The neurobehavior of Danio rerio is more sensitive to hydrolyzed fumonisin than to its prototype. Using low amount of test compounds, and being fast and visual, neurobehavioral study of Danio rerio is a suitable tool for the early stage toxicity screening of emerging toxicants (e.g. masked mycotoxins).

Objective To develop an enzyme-linked immunochromatographic test strip for the determination of amanita toxin in mushroom based on immunochromatography. Methods N-hydroxysuccinimide (NHS) and N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC) were used as activators, 6-aminohexanoic acid was introduced to obtain amanitin peptide hapten, and further conjugated with keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA) to prepare immunogen and coating antigen. Then, the immunogen was used to immunize Balb/c mice to prepare monoclonal antibodies. The colloidal gold immunochromatographic test strip for amanitin was successfully developed by preparing colloidal gold and gold labeled antibody, optimizing the concentration of coating antigen, secondary antibody and extracting solution, and then its cross reactivity, stability, repeatability, and accuracy were evaluated. Results The limits of detection of α-amatoxin, β-amatoxin, and γ-amatoxin peptide were 100, 20 and 50 μg/kg, respectively. The sensitivity was 100%, the false positive rate and false negative rate were 0%, and the results were consistent with the existing instrumental methods without cross reaction with other mushroom toxins. Conclusion The test strip has the characteristics of simple operation, high repeatability and good stability, and is suitable for on-sites creening and rapid detection of amanitin in mushrooms.

Objective To establish a qualitative screening method for 29 kinds of mycotoxins in grains based on QuEChERS dSPE EMR-Lipid and liquid chromatography-quadrupole time of flight-mass spectrometry. Methods The sample was extracted by 20 mL 70% acetonitrile (containing 1% formic acid), purified by modified QuEChERS method, electrospray ionization, positive ion sweeping, sequential window acquisition of all theoretical mass spectra. Results The established method included a database of primary precision mass, secondary mass spectrometry, and retention time. This method enabled rapid screening of 29 kinds of mycotoxins in soybean, corn, rice, and wheat. The screening limits of detection of ranged from 0.005 to 0.050 mg/kg. The method met the basic screening requirements. Conclusion The method is simple, specific, stable and reliable. The method enables the processing and qualitative screening of large volumes of samples from soyabean, corn, rice and wheat in a short time. It has high application value.

Objective To establish a method for the simultaneous determination of 10 kinds of phytotoxins, including tripterygium wilfordii and aconite in honey by ultra performance liquid chromatography-tandem mass spectrometry. Methods The samples were extracted by vortexing with 1% formic acid water-70% acetonitrile water solution. After high-speed centrifuged, added appropriate amount of primary secondary amine (PSA) to the supernatant, and shaked and mixed evenly, passed through 0.22 μm filter membrane, then determined and analyzed by the instrument. The matrix working curve was used for quantification by the external standard method. Results The limits of detection of 10 kinds of phytotoxins were 0.03-1.90 μg/kg. The 10 kinds of phytotoxins showed good linearity in a certain range of mass concentration with the correlation coefficients were all greater than 0.999. The average recovery rates of toxins ranged from 89.5% to 113.8% at 3 kinds of different concentration spiked levels, and the relative standard deviations of 0.5%-8.7%. Conclusion The method is convenient, sensitive and accurate, and provides technical support for rapid screening of phytotoxins in emergencies. It is suitable for simultaneous determination of various phytotoxins in honey samples, especially in batch samples.

Objective To compare the detection results of aflatoxin B₁ (AFB₁) content in various matrices such as rice, wheat products, and peanut products using 2 kinds of different pretreatment methods: Fully automated immunomagentic bead purification and immunoaffinity column pretreatment method. Methods After extraction with methanol:water (70:30, V:V), a portion of the extract was purified using the immunoaffinity column method with an AFB₁-specific immunoaffinity column, while another portion of the extract was processed by a fully automated immunomagnetic bead purification system paired with an immunomagnetic bead kit. Finally, both purified extracts were analyzed using high performance liquid chromatography coupled with post-column derivatization for detection. Results The efficacy of the immunomagetic bead purification kit and the column efficiency of the immunoaffinity column were both greater than 95%, which could meet the experimental requirements. Within mass concentration range of 1.00-50.00 ng/mL, the linear correlation coefficient (r) was 0.99993, indicating a good linear relationship. The 3 level spiked recovery experiments were conducted in rice matrix (n=6), and the recovery rates of the 2 kinds of pretreatment methods ranged from 98.2%-106.0%, with a relative standard deviation range of 1.0%-5.0%; single level spiked recovery experiments were conducted in wheat products (n=6), with a recovery rate exceeding 80% and a relative standard deviation of 3.7%-7.2%. Meanwhile, the 2 kinds of methods were used to detected AFB₁ positive peanut products and the quality control sample of corn flour matrix, their results were subjected to t-test, which showed no significant difference. Further, Bland-Altman statistical analysis was carried out on the results obtained from the quality control samples of corn flour matrix after 2 kinds of pretreatment methods were used. The results showed that the 2 kinds of methods could replace each other in the detection of AFB₁ in this matrix. The purification step of the immunoaffinity column method was time-consuming, 20 batches of samples take about 3-4 hours. And could only be manually operated, which generated about 1000 mL waste liquid; while the immunomagetic bead method used a fully automatic magnetic bead purifier, which automatically completed 20 batches of samples in 40 minutes at one time, with almost no waste liquid generated. Conclusion The fully automated immunomagnetic bead purification method and the immunoaffinity column method both can achieve good results in detecting AFB₁ in various matrices. Also, the immunomagnetic bead purification method is more efficient, easy to handle, generates less waste liquid, and the cost can be reduced by about 50%.

Objective To evaluate the heavy metal contamination characteristics and health risks of Ziziphus jujuba Mill. from 3 major production regions (Jiao cheng Jun Ziziphus jujuba Mill., Tai gu Hu ping Ziziphus jujuba Mill., and Xiang fen Guan tan Ziziphus jujuba Mill.) in Shanxi Province. Methods Sample pretreatment was performed using a microwave digestion system, followed by quantitative analysis of Cr, Ni, Pb, Cd, As, and Hg in 180 Ziziphus jujuba Mill. samples via inductively coupled inductively coupled plasma-mass spectrometry (ICP-MS). Experimental data were standardized using Microsoft Excel 2022, and non-parametric statistical analyses (Kruskal-Wallis H test, Spearman’s rank correlation) were conducted with SPSS 26.0 IBM to investigate elemental distribution patterns and regional correlations. Health risks were assessed using the United States Environmental Protection Agency (USEPA) model with exposure parameters. Results A highly sensitive multi-element simultaneous detection method was established with a limit of detection of 0.003 to 0.010 mg/kg, with a recovery rates of 92% to 108% and a precision of 2.9% to 4.5%. Key findings included: (1) Hg was undetected in all regions, while Cr and Ni were universally detected, Pb detection rates exhibited regional differences, with the highest in Xiangfen, Cd detection rates were notably higher in the Taigu; (2) The studied elements exhibited significant spatial heterogeneity; (3) Pb, Ni and Cr in Jiao cheng Jun Ziziphus jujuba Mill. and Xiang fen Guan tan Ziziphus jujuba Mill. exhibited a highly significant positive correlation, while the correlations of the same elements between Tai gu Hu ping Ziziphus jujuba Mill. and Xiang fen Guan tan Ziziphus jujuba Mill. showed a synchronous enhancement; (4) health risk assessment identified potential non-carcinogenic risks for Cr and Pb in Xiangfen, and the daily intake of As approached but remained below the international threshold. Conclusion This study systematically map the heavy metal contamination profile of Shanxi Ziziphus jujuba Mill. for the first time and propose region-specific grading standards for pollutants, providing a scientific basis for improving the quality and safety regulatory framework of jujube products.

Objective To establish a method based on ultra performance liquid chromatography-quadrupole time of flight high resolution-mass spectrometry (UPLC-Q-TOF-MS) use as a rapid screening method for the illegal addition of 302 kinds of drugs in Chinese veterinary medicine. Methods A high-resolution mass spectrometry database containing information such as the names, molecular formulas, and exact mass numbers of 302 kinds of drugs was established. Samples were extracted with methanol and then analyzed by UPLC-Q-TOF-MS. A sample was considered as a suspected positive if the retention time deviation was less than 0.2 min, the mass error was less than 5 ppm, the isotopic ratio deviation was less than 5%, and the library matching score of the main characteristic fragment ions was greater than 80. Results The method exhibited good selectivity, with a minimum detection concentration as low as 50 ng/mL for the target substances (100 ng/mL for tetracyclines, penicillins, estrogens, and nonsteroidal anti-inflammatory drugs; 200 ng/mL for aminoglycosides). This enabled the efficient screening of 302 kinds of illegally added drugs. In the screening of actual samples, 7 batches of suspected positive samples were detected. Conclusion This approach is applicable for the screening of illegal additives in various veterinary Chinese medicines, providing effective technical support for the quality control of veterinary Chinese medicines.

Objective To understand the effect of sodium diacetate on the growth and toxin production of Burkholderia gladioli in fresh wet rice noodles medium. Methods A total of 10 Burkholderia gladioli strains isolated from wet rice noodles samples and rice raw materials and purchased by the strain preservation center were used as research objects. The strains were inoculated into the medium supplemented with different proportions of sodium diacetate to study the growth and toxin production of the strains in the medium. Results The growth of 10 strains of Burkholderia gladioli in BHI broth was consistent. Sodium diacetate had consistent inhibitory effects on different bacterial strains. When the addition of sodium diacetate in BHI broth was more than 0.1%, the growth of 10 strains of Burkholderia gladioli was significantly inhibited, and there was no bacterial growth when the addition reached 0.2%. In BHI semi-solid medium and wet rice noodles medium, when sodium diacetate was added more than 0.1%, the growth of Burkholderia gladioli was significantly weakened or even completely inhibited, and the production of bongkrekic acid was also greatly reduced. Conclusions Sodium diacetate can effectively inhibit the growth of Burkholderia gladioli and reduce the production of bongkrekic acid. It is expected to become a safe and effective preservative or compound preservative that can act on Burkholderia gladioli, reducing the risk of contamination by Burkholderia gladioli at a more affordable cost in the industry.

Objective To establish a visual detection method of Salmonella based on recombinant enzyme polymerase amplification-CRISPR/Cas12a. Methods In this study, recombinase polymerase amplification (PRA) was combined with clustered regularly interspaced short palindromic repeats/associated protein 12a (CRISPR/Cas12a) system. RPA primers and CRISPR-derived RNA (crRNA) were designed and synthesized based on the target invA gene of Salmonella. Fluorescence and test strip methods were employed to read the results. The optimized RPA-CRISPR/Cas12 detection system were evaluated for specificity and sensitivity, and was applied to the detection of food samples. Results Nano gold test strip base on nucleic acid were developed. The established RPA-CRISPR/Cas12 detection method could specifically detecting Salmonella with a sensitivity of 80 CFU/mL within 1.5 h. Used this method to detect 21 kinds of food samples, the results from fluorescence and test strip read were consistent, with a Salmonella detection rate of 4.8%, which was completely consistent with the results of the national standard method. Conclusion The Salmonella RPA-CRISPR/Cas12a visual detection method established in this study has high specificity and sensitivity and is valuable for on-site rapid detection of Salmonella.