Catechol detection based on a two-dimensional copper-based metal-organic framework with high polyphenol oxidase activity

In this work, a novel sensing strategy for catechol was successfully developed based on a two-dimensional copper-based metal-organic framework (2D Cu-MOF) with high polyphenol oxidase activity. The 2D Cu-MOF was prepared from dimethylimidazole and Cu 2+ by stirring in a mixture solvent of methanol and water. We firstly found that the 2D Cu-MOF exhibited high polyphenol oxidase (PPO) activity by catalyzing the typical PPO substrate to produce a red color. And the PPO activity of the 2D Cu-MOF was higher than those of the other two reported PPO-mimicking enzymes at the same mass concentration. Subsequently, based on the effective PPO activities of the 2D Cu-MOF, we established a simple and rapid colorimetric method for detecting catechol with a detection limit of 0.35 µg mL −1 . This method was also used to detect catechol in city water with satisfying results.