The Electrogenerated Chemiluminescence Of Luminol On Graphene Based Nanocomposites Modified Electrodes

Electrogenerated chemiluminescence (ECL) is the most active frontier inelectroanalytical chemistry, which has been widely applied in life science, drug analysis,immunoassays, as well as environmental science. Graphene has a large specific surfacearea, excellent electron transport capability, and good compatibility with other particles.Therefore, graphene-based nanomaterials modified electrode is another interesting area inelectroanalytical chemistry.In this thesis, graphene modified glassy carbon electrode, polyaniline(PANI)/electrochemically reduced graphene oxide (GR) modified glassy carbon electrode,and gold nanoparticle (GNP)/carbon nanotube (CNT)/graphene (GR) modified glassycarbon electrode were prepared and characterized. Electrogenerated chemiluminescence(ECL) of luminol was studied on these modified electrodes in neutral phosphate buffersolution (PBS) to explore the electrocatalytic activity of nanocomposites basednanocomposites, which will provide the theory and application support for thedevelopment of ECL sensors. The main results are as follows:1. Graphene oxide (GO) modified glassy carbon electrode, electrochemically reducedgraphene oxide (GR) modified glassy carbon electrode were prepared and characterized byFT-IR, scanning electron microscopy (SEM) and electrochemical techniques, respectively.Electrogenerated chemiluminescence (ECL) of luminol was studied on these modifiedelectrodes in neutral phosphate buffer solution. The results showed that the anodic ECLemission of luminol was inhibited greatly and only one cathodic ECL peak was obtained atthe GR modified electrode. The intensity of the cathodic ECL emission at the GR modifiedelectrode increased two magnitudes compared with the GO modified electrode and the bareelectrode, mainly due to the graphene modified layer having strong adsorption of oxygen,thereby enhancing the luminol cathodic ECL emission. The results revealed that graphenemodified electrode could increase the detection sensitivity of luminol ECL and will expandthe application of luminol ECL sufficiently.2. Polyaniline (PANI) modified glassy carbon electrode, electrochemically reducedgraphene oxide (GR) modified glassy carbon electrode, and PANI/GR modified glassycarbon electrode were prepared and characterized by atomic force microscopy, FT-IR andelectrochemical techniques, respectively. Electrogenerated chemiluminescence (ECL) ofluminol was studied on these modified electrodes in neutral phosphate buffer solution(PBS). The results showed that PANI and graphene form multi-layer on the bare electrode.In neutral solution, the intensity of anodic ECL in the PANI/GR modified glassy carbon electrode at0.50V was enhanced near two magnitudes compared with two other modifiedelectrodes. The above results might bring new applications of luminol ECL inphysiological conditions.3. Graphene (GR) modified glassy carbon electrode, carbon nanotube(CNT) modifiedglassy carbon electrode, CNT/GR composite materials modified glassy carbon electrodeand gold nanoparticle (GNP)/CNT/GR modified glassy carbon electrode were preparedand characterized by atomic force microscopy, FT-IR, respectively. Electrogeneratedchemiluminescence (ECL) of luminol was studied on these modified electrodes in neutralPBS. The results showed that the enhancing effect of the CNT/GR composite to luminolECL is stronger than that of GR or CNT. When gold nanoparticles have beenelectrodeposited on CNT/GR modified glassy carbon electrode, luminol ECL intensity wasfurther increased. Therefore, the composite material is likely to expand the application ofluminol ECL.