Construction of Ce-MOF@COF hybrid nanostructure with controllable thickness for the electrochemical sensitive detection of metol

Covalent organic frameworks (COFs), a newly emerging kind of porous material, have gained extensive attention due to their fascinating structural features. However, the superiority of COFs as electrochemical sensing materials has not yet been adequately explored. Herein, a new type of core–shell metal–organic framework (MOF)@COF composites are synthesized through in situ growth of TAPB-DMTP-COF on the pre-synthesized Ce-BDC core. The thickness of the COF shell can be controlled to 20–50 nm by adjusting the Ce-MOF mass. It is found that the obtained MOF@COF composite possesses a larger electrochemical active area and faster electron transfer kinetic than its single component. As a case application of this composite, it has been employed as a sensing material for voltammetric detection of metol, where a linear range from 0.1 − 200 μM and a detection limit of 30 nM have been obtained. This study provides a new strategy to synthesize COF-based electrode materials as well as to explore their electrochemical properties and applications.