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).