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

Abstract

This Communication is dedicated to Prof. Hubert Girault on the occasion of his 65 th birthday.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.

Cobalt-H3BTC Metal Organic Framework-Based Electrochemical Nanosensor for Hydrogen Peroxide

“…Fabrication of open carbon nanopipettes.-CNPs were prepared according to the previously reported protocol. 18,21 Briefly, open nanopipettes were prepared by pulling quartz capillaries (1.0 mm o.d., 0.5/0.7 mm i.d. ; Sutter Instrument Company) with a laser pipette puller (P-2000, Sutter Instruments).…”

“…Electrode modification with CoMOF.-CoMOF electrosynthesis was conducted according to the previously published protocol 18 with some modifications. Cobalt (II) nitrate trihydrate (4.5 mmol) and sodium nitrate (100 mmol) were dissolved in 5 ml of water (solution A).…”

“…[10][11][12][13][14][15][16] We recently showed that a copper-based MOF (HKUST-1 17 ) can be electrochemically synthesized inside an open carbon nanopipette (CNP, i.e., a pulled quartz nanopipette with a carbon-coated inner wall) to prepare the first MOF-based electrochemical nanosensor. 18 The easy to fabricate MOF/CNP nanoelectrodes showed a good sensitivity to H 2 O 2 . An anticipated drawback of this sensor is that the measured current is due to peroxide reduction, so that the solution needs to be degassed to avoid potential interference of dissolved dioxygen.…”

Sensitive Current Sensor Based on a Lanthanide Framework with Lewis Basic Bipyridyl Sites for Cu2+ Detection

“…In this context, when MOFs do not have fluorescence properties, ion detection will not be possible. However, some recent work in detection revealed that, when a chemical reaction occurs within the nanopores of MOFs, the current through the holes will change significantly, and this variation of current can also be employed for the detection of ions. − Moreover, using this method, Liu and co-workers successfully constructed an artificial sodium ion-selective ionic device with a selectivity ratio of Na + /K + up to 15 via growing a crown ether crystal in situ in the tip of the glass micropipette . This study opens the door for the construction of a variety of artificial ion channels with adjustable selectivity for metal ions.…”

Alternative protein encapsulation with MOFs: overcoming the elusive mineralization of HKUST-1 in water

“…5A). 22–24 In the case of the biocomposites, CytC@H1 exhibits a similar activity than H1, while CytC@HK1 reveals a sharp activity enhancement, which is attributed to its characteristic permanent porosity that enables the transfer of substrates. Control analysis over the physical mixtures reveal that combination of CytC and H1 perform as free CytC (Fig.…”