Synthesis of a three-dimensional porous Co3O4 network interconnected by MWCNTs and decorated with Au nanoparticles for enhanced nonenzymatic glucose sensing

Possessing porous structure and fast electron transfer rate is vital for regulating electrocatalytic performance of nanomaterials. Considering the low conductivity and poor electrocatalytic activity of Co3O4, we report a hybrid composite of porous Co3O4 interconnected by MWCNTs and decorated with Au nanoparticles (Co3O4/MWCNTs/Au) for nonenzymatic glucose sensing due to the importance of glucose in many fields. The nanocomposite is synthesized by inserting MWCNTs into ZIF-67 precursor, decorating Au3+ on ZIF-67/MWCNTs, and then calcinating at high temperature. TEM results reveal that MWCNTs were inserted into porous Co3O4 and Au nanoparticles were successfully decorated on surface of Co3O4/MWCNTs, which made the nanocomposite look like a three-dimensional interconnected electrically conducting network. Electrochemical results display that the presence of MWCNTs and Au nanoparticles significantly facilitated electron transfer rate and improved electrocatalytic activity of Co3O4, therefore enabling the sensor based on Co3O4/MWCNTs/Au to detect glucose in a wide linear range of 0.2 mu M -1.1 mM with a high sensitivity of 1138.4 mu A mM(-1) cm(2) and a low detection limit of 0.1 mu M (S/N = 3). This study provides a strategy to tailor electrocatalytic performance of nanomaterail and also provides a promising sensing material for glucose detection.