Atropine (AT) is an anticholinergic drug. AT is abundantly in Datura plant seeds. Fe3O4@Zn/Mg MOF (Fe3O4@MOF) composite was synthesized. The compound had a high peroxidase-like activity in a chemiluminescence (CL) reaction. Addition of AT quenched CL. The linear range and limit of detection were 5–600 μg L1 and 2 102 μg L1. This method is fast, reversible, and selective, without biodegradability effects, high accuracy, and precision for measuring AT in the Datura plant.