Facile preparation of graphene nanoribbon/cobalt coordination polymer nanohybrid for non-enzymatic H2O2 sensing by dual transduction: electrochemical and fluorescence

Abstract

A novel graphene nanoribbon (GNR)/cobalt coordination polymer (MCPs) composite (MCPs@GNR) is prepared by in situ reduction of graphene oxide nanoribbon (GONR) with simultaneous growth of MCPs nanoparticles on its surface. The morphology and structure are investigated by high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform-infrared spectroscopy, X-ray diffraction and Raman spectroscopy. Results indicate that MCPs nanoparticles having dia. ∼6 nm are successfully deposited on GNR to form a hybrid conducting network. Analysis of the performance of the MCPs@GNR composite shows high non-enzymatic electrocatalytic activity for H₂O₂ reduction with a low limit of detection ∼60 nM at S/N = 3. The fluorescence of MCPs provides an optical feature which is also applied here for the detection of H₂O₂. The fluorescence quenching of MCPs@GNR can be achieved by addition of H₂O₂ which shows linearity over a range of increasing concentration of 10 μM to 150 μM.