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

Abstract

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 × 10⁻⁶ to 1.0 × 10⁻² mol L⁻¹, a high sensitivity of 483.51 μA mM⁻¹ cm⁻² and a low detection limit of 0.67 μmol 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.