Ractopamine, as a feed additive, has attracted much attention due to its excessive use, leading to the damage of the human nervous system and physiological function. Therefore, it is of great practical significance to establish a rapid and effective method for the detection of ractopamine in food. Electrochemical sensors served as a promising technique for efficiently sensing food contaminants due to their low cost, sensitive response and simple operation. In this study, an electrochemical sensor for ractopamine detection based on Au nanoparticles functionalized covalent organic frameworks (AuNPs@COFs) was constructed. The AuNPs@COF nanocomposite was synthesized by in situ reduction and was characterized by FTIR spectroscopy, transmission electron microscope and electrochemical methods. The electrochemical sensing performance of AuNPs@COF-modified glassy carbon electrode for ractopamine was investigated using the electrochemical method. The proposed sensor exhibited excellent sensing abilities towards ractopamine and was used for the detection of ractopamine in meat samples. The results showed that this method has high sensitivity and good reliability for the detection of ractopamine. The linear range was 1.2–1600 μmol/L, and the limit of detection (LOD) was 0.12 μmol/L. It is expected that the proposed AuNPs@COF nanocomposites hold great promise for food safety sensing and should be extended for application in other related fields.

Ethyl carbamate (EC) is a kind of genotoxic and carcinogenic substance and potentially harmful to human health. In this study, simple and effective removal of EC from liquor samples by using the magnetic mesoporous adsorbent (Fe3O4@COFs) was investigated. Gas chromatography and triple quadrupole tandem mass spectrometry (GC‐MS/MS) was used to monitor the whole of adsorption process. The results showed that the adsorbent has high efficiency and fast adsorption capacity. Under the optimized adsorption parameters, pseudo‐first‐order and pseudo‐second‐order kinetic models were employed to reveal the underlying sorption mechanism. Results indicated that the adsorption of EC on Fe3O4@COFs is more consistent with the pseudo‐second‐order model. Furthermore, an effective method for the adsorption and detection of EC was successfully developed, which exhibited good linearity with R2 ranging from 0.9954 to 0.9998, satisfactory recoveries in the range of 86.9%–116.2%, and the relative standard deviations (RSD) was lower than 5.8%. Fe3O4@COFs showed good stability and excellent performance in removing EC from liquor samples. It is expected that the proposed magnetic COFs hold great promise for liquor sample pretreatment and be extended for application in other fields.

The increasing public attention on unceasing food safety incidents prompts the requirements of analytical techniques with high sensitivity, reliability, and reproducibility to timely prevent food safety incidents occurring. Food analysis is critically important for the health of both animals and human beings. Due to their unique physical and chemical properties, nanomaterials provide more opportunities for food quality and safety control. To date, nanomaterials have been widely used in the construction of sensors and biosensors to achieve more accurate, fast, and selective food safety detection. Here, various nanomaterial-based sensors for food analysis are outlined, including optical and electrochemical sensors. The discussion mainly involves the basic sensing principles, current strategies, and novel designs. Additionally, given the trend towards portable devices, various smartphone sensor-based point-of-care (POC) devices for home care testing are discussed.