Designing boron-doped carbon dot-functionalized COFs for fluorescence screening and liquid chromatography tandem mass spectrometry detection of toxins

In recent years, mushroom poisoning has been one of the most important factors of food poisoning in China, timely identification of the toxins contained in mushrooms is crucial for the treatment of patients. In this study, boric acid carbon dots (BA-CDs) can undergo specific boron affinity reactions with amatoxins toxins containing o-dihydroxyl groups by means of boric acid groups. Functional covalent organic framework (COF) and BA-CDs were combined to design a adsorbent with boric acid group (COF@VBC@BA-CDs) was designed to meet the requirements of both fluorescent and pretreated materials for amatoxins. The mushrooms and urine samples were rapid screening using fluorescence detection, and then, for positive samples, the target analytes on the COF@VBC@BA-CDs are collected and eluted for next liquid chromatography tandem mass spectrometry (LC-MS/MS) detection. According to the fluorescence characteristics of COF@VBC@BA-CDs, the fluorescence quenching intensity was linearly correlated with the concentration (2–200 μg/L) and the detection limit was 1.2 μg/L. Meanwhile, the detection limit of LC-MS/MS was 0.5 μg/kg for musroom and 0.2 μg/L for urine, as well as the recovery rate was 72.7–110.1%. This noval method meets the methodological requirements and can be used for actual sample analysis.