Microflowers Comprised of Cu/Cu_xO/NC Nanosheets as Electrocatalysts and Horseradish Peroxidase Mimics

Abstract

The preparation of various nanomaterials with hierarchical structure from metal–organic frameworks (MOFs) has attracted a lot of attention due to their abundant diversity in composition and structure. In this work, we developed a method to synthesize a three-dimensional (3D) Cu/Cu x O/NC (nitrogen carbon) composite by pyrolysis of Cu-MOF. The obtained Cu/Cu x O/NC composite has a flower-like structure assembled with nanosheets. It displays both excellent electrochemical catalytic and mimic enzyme activities. It was successfully applied to fabricate an electrochemical glucose sensor which has a linear response in the range of 0–2.0 mM and 2.0–5.0 mM with a detection limit of 3.5 μM, and electrochemical measurements indicate that the Cu/Cu x O/NC-modified electrode possesses high selectivity toward glucose. Moreover, Cu/Cu x O/NC also acted as a horseradish peroxidase (HRP) mimic enzyme and displayed obvious enzymatic catalytic activities for tetramethylbenzidine (TMB) and dopamine (DA) in the presence of H2O2. To demonstrate the proof-of-concept, it was used to construct an enzymatic sensor for glucose. The obtained 3D Cu/Cu x O/NC nanostructures present good prospects in sensor platform construction for other biomolecules.

Enzyme‐free Electrochemical Detection of Hydrogen Peroxide Based on the Three‐Dimensional Flower‐like Cu‐based Metal Organic Frameworks and MXene Nanosheets†

“…[ 31 ] To further verify the crystal structure of nanomaterials of Cu‐MOF and MXene, X‐ray diffraction (XRD) was conducted. As shown in Figure 1D, the XRD spectrum of Cu‐MOF is consistent with the reported diffraction pattern of Cu‐MOF, [ 33 ] indicating the successful synthesis of Cu‐MOF. The MXene nanosheets were prepared by etching Al of Ti 3 AlC 2 , and the diffraction pattern of MXene nanosheets contains (002), (104) and (107) diffraction peaks of Ti 3 AlC 2 , while other strong peaks belonging to Ti 3 AlC 2 disappear with the successful etching of Al, indicating the successful synthesis of MXene nanosheets.…”

“…Cu‐MOF is synthesized by a simple one‐step hydrothermal process, and the synthesis method is similar to the literature. [ 33 ] 0.5 mmol NH 2 ‐BDC and 1.0 mmol Cu(NO 3 ) 2 ·3H 2 O were added into 10.0 mL DMF to form a homogeneous solution under stirring. Subsequently, the mixed solution was transferred into a 50 mL Teflon‐lined stainless‐steel reactor and reacted at 100 °C for 24 h. After naturally cooling to room temperature, the precipitates were carefully collected by centrifugation, and then washed with ethanol several times, finally dried at vacuum overnight at 60 °C.…”

Polyaniline Nanowire Arrays Deposited on Porous Carbon Derived from Raffia for Electrochemical Detection of Imidacloprid

“…RPC@PANI modified glass carbon electrode (RPC@PANI/GCE), Ag/AgCl (in saturated KCl) and platinum wire were acted as working, reference and counter electrodes, respectively. The working electrode was prepared by dripping RPC@PANI dispersion solution (5.0 μL) on polished GCE [13] and dried in air, followed by dripping 3.0 μL ethanol solution containing nafion (0.5 wt %). Phosphate buffered solution (PBS, 0.1 M, pH 7.4) was acted as electrolyte.…”

A New Era of Metal–Organic Framework Nanomaterials and Applications

“…28 A microflower structure was produced by pyrolysis of a copper-based MOF, showing electrochemical catalytic and enzyme-mimicking activities. 29 The porous nature of MOFs enables them to be ideal platforms for metal doping and immobilization toward advanced catalysis. Palladium-immobilized MOFs were employed as catalysts for the hydrogenation of aromatic aldehydes under visible light.…”