Voltammetric determination of hydrogen peroxide using AuCu nanoparticles attached on polypyrrole-modified 2D metal-organic framework nanosheets.

AuCu/PPy/Cu-TCPP nanocomposites were synthesized by attaching AuCu nanoparticles to a polypyrrole (PPy)-modified 2D Cu-TCPP metal-organic framework nanosheet; Cu-TCPP can exhibit catalytic activity for the reduction of H2O2. Based on the nanocomposite, a new method for the determination of H2O2 was established. The morphology of the AuCu/PPy/Cu-TCPP was analyzed by transmission electron microscopy. Cu-TCPP exhibited a 2D nanosheet with obvious wrinkles, and a large amount of AuCu was uniformly attached to PPy/Cu-TCPP. The composition and structure were studied by X-ray diffraction, FTIR, and X-ray photoelectron spectroscopy. At the optimal working potential and scan rate of - 0.55 V(vs. SCE) and 100 mV/s, respectively, electrochemical studies indicated that in N2-saturated supporting electrolyte, the method showed good catalytic performance for H2O2, with a detection limit of 6.67 nM (S/N = 3), a linear range of 7.10 µM-24.10 mM, and a sensitivity of 35.0 µA mM-1 cm2. Compared to H2O2 methods based on related materials, this method exhibits a wide linear range, and the detection limit is down to nanomolar. Graphical abstract Schematic presentation of the preparation of AuCu/PPy/Cu-TCPP nanocomposites. AuCu/PPy/Cu-TCPP nanocomposite was prepared by loading gold-copper (AuCu) bimetallic nanoparticles with good catalytic properties on two-dimensional copper (II)-porphyrin (Cu-TCPP) nanosheet metal-organic framework material, whose conductivity was improved by polypyrrole (PPy). A method for the determination of hydrogen peroxide by voltammetric was established.

Non-enzymatic electrochemical hydrogen peroxide sensing using a nanocomposite prepared from silver nanoparticles and copper (II)-porphyrin derived metal-organic framework nanosheets.

A non-enzymatic hydrogen peroxide (H2O2) electrochemical sensor material was prepared from silver nanoparticles and a 2D copper-porphyrin framework (MOF). The structure and morphology of the nanocomposite were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The results showed that the MOF has a two-dimensional sheet structure, and a large number of Ag NPs are uniformly attached to it. The MOF also acts as a peroxidase mimic. The sensor has excellent catalytic performance in terms of H2O2 reduction. Figures of merit include (a) an electrochemical sensitivity of 21.6 µA mM-1 cm-2 at a typical working potential of -0.25 V (vs. SCE), (b) a detection limit of 1.2 µM (at S/N = 3), and (c) a linear response range that extends from 3.7 µM to 5.8 mM. Compared to other sensors of the same type, the linear range of the sensor is extended by an order of magnitude. Graphical abstract Silver nanoparticles (Ag NPs) were reduced with sodium borohydride (NaBH4) on the surface of copper(II)-porphyrin (Cu-TCPP) nanosheets prepared with the assistance of polyvinylpyrrolidone (PVP). Their synergistic effect improved the performance of H2O2 sensor fabricated by immobilizing Ag NPs/Cu-TCPP nanocomposites on glassy carbon electrodes (GCE).