Urchin-like covalent organic framework microspheres for electrochemical organophosphorus pesticide sensing

Organophosphorus pesticides (OPs) pose serious risks to food safety and environmental health, but their rapid, sensitive detection is difficult. We developed TB-TD-COF, an urchin-like covalent organic framework, for acetylcholinesterase (AChE)-based electrochemical sensing. Synthesized via one-step room-temperature imine condensation, its thiophene-rich structure enhances electron transfer, and its microsphere morphology aids AChE immobilization and analyte transport. The TB-TD-AChE biosensor detects methyl parathion across a wide linear range (10^-10-10^-6 g mL^-1) with a low detection limit (2.13 × 10^-13 g mL^-1), plus good reproducibility, stability, and performance in river water samples.