Self-assembly preparation of gold nanoparticle decorated 1-pyrenemethylamine functionalized graphene oxide-carbon nanotube composites for highly sensitive detection of nitrite

Herein, we report a simple and attractive self-assembly strategy for preparing graphene oxide-multiwalled carbon nanotube-(1-pyrenemethylamine)-gold (GO-MWCNT-PMA-Au) nanocomposites using 1-pyrenemethylamine (PMA) as a coupling agent. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). Further, a non-enzymatic nitrite sensor was fabricated by immobilizing GO-MWCNT-PMA-Au nanocomposites on a glassy carbon electrode (GCE). To obtain the optimal electrochemical experimental conditions, the effects of pH value and the volume of the as-prepared Au nanoparticle suspension were carefully investigated. Its electrochemical sensing properties were studied by cyclic voltammetry and differential pulse voltammetry. The electrochemical investigation showed that the GO-MWCNT-PMA-Au nanocomposites exhibited good catalytic performance for the oxidation of nitrite. The nitrite electrochemical sensor presented a wide linear range from 2.0 x 10(-6) to 1.0 x 10(-2) mol L-1, a high sensitivity of 483.51 mu A mM(-1) cm(-2) and a low detection limit of 0.67 mu mol L-1 at a signal-to-noise ratio of 3 (S/N = 3). It also exhibited good anti-interference capability and stability. This paper provides a self-assembly strategy for preparing nanocomposites which are used to construct improved electrochemical sensors.