Real-time selective pesticide detection using catalytic behavior of zwitterionic conjugated polymer

We focus on the catalytic behavior of zwitterionic conjugated polymer (ZIPF) as a novel sensing platform for a toxic pesticide, namely diquat (DQ). The synthesized ZIPF with the oxidative polymerization method exhibits high photoluminescence stability in water over the pH range (1–13). We show that the ZIPF rapidly degrades the toxic DQ into the highly fluorescent intermediate diquat monopyridone (DMP) at pH 13 without any pretreatment, leading to real-time, highly sensitive, and selective detection. The present analytical method responses within few seconds and can detect up to excellent nanomolar level of DQ (3.48 nM) in water. The sensing mechanism with the catalytic behavior of ZIPF is carefully investigated.