Metal-Organic-Framework-Based Electrochemical Nanosensor for Hydrogen Peroxide

Electrochemical applications of metal organic frameworks (MOFs) are of considerable current interest. Due to the large surface area exposed to solution, MOFs are potentially useful electrode materials for sensing inner-sphere analytes, such as reactive oxygen species. Herein, we electrodeposited copper benzene tricarboxylate MOF (HKUST-1) into the cavity of an open carbon nanopipette (CNP) to produce a CNP-MOF nanoelectrode. Unlike electronically conductive metal or carbon electrodes, the electrochemical response of CNP-MOFs relies on oxidation/reduction of Cu(I)/Cu(II) nodes in the porous nanostructure. Nevertheless, sigmoidal steady-state voltammograms with a well-defined plateau current have been recorded for simple redox mediators, for example, ferrocenemethanol. A linear calibration curve obtained for the hydrogen peroxide reduction suggests that CNP-MOFs can potentially be useful as nanosensors for peroxide.