A solution-based approach of chemical co-reduction of graphene oxide (GO) and HAuCl4 was used to prepare graphene/Au nanocomposite (GR/Au). The resulting hybrid material was characterized by scanning electron microscope and transmission electron microscope, which demonstrated that Au nanoparticles could been uniformly deposited on the GR sheets. Then, nanocomposite (GR/Au/ILs) of ionic liquids (ILs), GR and Au nanoparticles (NPs) were successfully prepared. Such a nanostructured composite greatly facilitated electron-transfer process and the sensing behavior for PQ detection, leading to remarkably improved sensitivity. The GR/Au/ILs modified glassy carbon electrode showed a broad linear range from 2.0 × 10−9 mol L−1 to 1.0 × 10−7 mol L−1, with a detection limit of 7.3 × 10−10 mol L−1 (S/N = 3) for PQ, along with good reproducibility and stability. At the same time, this sensor could be applied to the determination of PQ in real samples with satisfactory results.
