Defect-Engineered Luminescent Nanozyme with Enhanced Phosphohydrolase Activity for Degradation and Dual-Mode Detection of Paraoxon.

The excessive use of organophosphorus pesticides poses a substantial threat to both human health and the environment. Consequently, there is an urgent need for new methods that can quickly degrade and sensitively detect these compounds. A versatile nanozyme based on the biomimetic principle is an effective strategy to solve this problem. In this study, a multifunctional luminescent nanozyme Eu@Ce/UiO-67 composed of Eu and a bimetallic organic framework Ce/UiO-67 is developed for the degradation and dual-mode detection of paraoxon. The doping of Ce results in the formation of more defective structures in Eu@Ce/UiO-67, which significantly enhances the phosphatase activity of Eu@Ce/UiO-67 and the degradation efficiency of paraoxon. The hydrolysis product 4-nitrophenol (4-NP) shows a distinct UV-vis absorption in the visible light region and can quench the fluorescence of Eu@Ce/UiO-67 by the effect of photo-induced electron transfer (PET), thus achieving dual-mode detection of paraoxon by colorimetric and fluorescent methods. This study provides a new idea for the simultaneous monitoring and degradation of organophosphorus pesticides, expanding the boundaries of "integration of diagnosis and treatment" for environmental pollutants.