Post-synthetic modification fluorescence UiO-66-Eu immunochromatography for high-performance detection of sodium pentachlorophenoate

Sodium pentachlorophenate (PCP) is widely used as a herbicide, fungicide, or molluscicide. It is highly toxic, easily soluble in water, making it highly prone to diffusion and causing water and soil pollution. Through the food chain, it enters animal bodies and remains in food, causing toxicity to humans and animals. Therefore, establishing a rapid and simple detection method for PCP is crucial for human health and environmental protection. Herein, lanthanide metal Eu³⁺ was introduced into UiO-66-(COOH)₂ by post-synthesis modification, and the nanomaterials prepared based on this method have the advantages of both UiO-66-(COOH)₂ and Eu³⁺. The rigid skeleton structure of UiO-66-(COOH)₂ can protect the activity of antibody, the detection environment pH tolerance range of UiO-66-Eu is 3-11. While Eu³⁺ has long fluorescence lifetime, high fluorescence intensity, high signal-to-noise ratio, and low photobleaching rate. UiO-66-Eu-based immunochromatography assay was successfully applied in PCP detection with the detection limits of 0.84, 0.98, and 0.37 μg/kg for pork, chicken, and shrimp, respectively, which was up to 10-fold more sensitive than the reported ICAs. The recoveries ranged from 79.7 %-113.1 %, with the coefficient of variation from 6.6 %-17.1 %. Parallel detection of 30 samples by LC-MS/MS showed a good correlation with that of our proposed method (R² >0.98). This work not only provides a creative attempt for UiO-66-Eu based highly sensitive and strongly tolerant ICAs, but also guarantees human health and environmental protection.