▎ 摘　　要

As the sensing film on the electrode surface, some composites consisted of the conducing polymer and the different types of nanomaterials exhibit the improved electroconductivity and catalytic ability in comparison with those composed of the individual components. But their preparation generally requires a multi-step and relatively complicated process. Here a glassy carbon electrode (GCE) modified with poly(glyoxal-bis(2-hydroxyanil)) (PGBHA), amino-functionalized graphene quantum dots (afGQDs) and MnO2 nanoclusters (MnO2 NCs) was fabricated based on a one-pot protocol using the cyclic voltammetric scan. The scanning electron microscopy, infrared spectroscopy and X-ray photoelectron spectroscopy measurements confirmed the existence of the PGBHA-afGQDs film doped by MnO2 NCs on the GCE surface. The charge transfer on this chemically modified electrode could be well achieved, which was revealed by the cyclic voltammetry and electrochemical impedance spectroscopy. The prepared electrochemical sensor was employed for the simultaneous determination of vitamin B-2 (V-B2) and dopamine (DA) by using differential pulse voltammetry. The linear detection range of V-B2 and DA was obtained from 0.1 to 100 mu M under the optimized conditions and the detection limits were measured to be 0.04 mu M and 0.05 mu M, respectively.