Well-dispersed cobalt phthalocyanine nanorods on graphene for the electrochemical detection of hydrogen peroxide and glucose sensing

Cobalt phthalocyanine nanorods were non-covalently absorbed onto graphene (Gr) through a one-step microwave radiation-assisted synthesis, and a novel cobalt phthalocyanine nanorod-graphene nanocomposite (nanoCoPc-Gr) was obtained. The formation of nanoCoPc on the surface of Gr was characterized by UV spectroscopy, IR spectroscopy and high-resolution transmission electron microscopy (HRTEM). HRTEM demonstrated that the nanorods were well-dispersed on the surface of Gr. The electrochemical performance of this type of nanocomposite was further investigated. NanoCoPc-Gr accelerates the electron transfer, and a glassy carbon electrode modified with the complex exhibits excellent electrocatalytic activity towards hydrogen peroxide (H2O2). Based on the electrocatalytic oxidation towards hydrogen peroxide, an amperometric enzyme electrode sensitive to glucose is also described, which was achieved by the immobilization of glucose oxidase onto the nanoCoPc-Gr electrode. The proposed glucose biosensor displayed good amperometric response characteristics towards glucose in a 0.1 M buffer solution, such as a low overpotential (+500 mV vs. SCE), a fast amperometric response (approximately 3 s), a good linearity (R = 0.9999) with the concentration range from 1.67 x 10(-5) M to 1.60 x 10(-3) M, and a low detection limit of 1.46 x 10(-5) M (S/N = 3). (C) 2015 Elsevier B.V. All rights reserved.