A new fluorescent technique for pesticide detection by using metal coordination polymer and nanozyme

Abstract

Background: Chinese herbs have been widely used for thousands of years. In order to kill or control insects and fungus during the cultivation of herb plants, pesticides have played a significant role. More than 30 kinds of pesticides have been documented in the latest version of Chinese Pharmacopoeia. It is urgent to develop new analytical methods for pesticide detection. Methods: A fluorescent detection system was established by using Cerium based fluorescent polymer and Sm-CeO2. As a new doped nanozyme, Sm-CeO2 exhibits OPH-like activity to hydrolyze OPP pesticide. Results: The morphology of the prepared CFP and Sm-CeO2 were characterized. The optimal conditions for CFP synthesis are CeCl3 (16 mmol L-1, 200 μL), ATP (4 mmol L-1, 200 μL) and Tris buffer (5 mmol L-1, 500 μL, pH 8.0). Sm-CeO2 shows the best mimic activity to hydrolyze OPP pesticide at pH = 8.0. The results exhibit good linear relationship between fluorescent quenching effect and MP in the range of 2-50 μmol L-1. Finally, this fluorescent technique was successfully applied in Poria cocos and Semen Coicis sample. Conclusions: It is the first report on OPP detection by using CFP and doped nanozyme. The successful application in real sample indicates this method is a rapid, reliable strategy to detect OPP in Chinese herbs.