| In this dissertation, the basic concepts of chemiluminescence (CL), the CL reaction systems and the principle of CL analysis were firstly introduced, and the application of magnetic nanomaterials in the field of CL analysis was reviewed. Magnetic nanoparticles (MNPs) triggered considerable attentions in the past several decades due to their unique physical-chemical properties, such as superparamagnetism,biocompatibility, strong adsorption ability and easy separation under external magnetic fields. In recent years , assembling MNPs onto the surface of graphene and graphene oxide (GO) sheets to obtain MNPs functionalized graphene hybrids becomes a hot research topic due to their new and enhanced multi-functionalities, which holds a great appeal for a wide range of applications in catalysis, drug delivery, medical imaging and removal of contaminants from wastewater. Up to now, magnetic GO or graphene hybrids with excellent CL activity have rarely been reported. And it is important to synthesized a kind of material with both excellent CL properties and magnetic performance for constructing CL interface in label-free bioassays. In this dissertation,N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and CoFe2O4 MNPs functionalized graphene nanomaterials (ABEI/CoFe2O4/GNs) were successfully synthesized by virtue of magnetic and catalytic properties of CoFe2O4 MNPs. The magnetic performance and CL/ECL properties of ABEI and CoFe2O4 MNPs functionalized graphene hybrids were investigated. The CL/ECL mechanism was explored.A facile approach was developed for the synthesis of novel ABEI and CoFe2O4 MNPs functionalized graphene hybrids with CL/ECL activity and magnetic properties for the first time. CoFe2O4 MNPs were firstly obtained via a one-step hydrothermal process, then ABEI as a CL reagent was assembled on the surface of graphene functionalized by non-covalent strategy to obtain ABEI/CoFe2O4/GNs, The morphology,structure and surface composition of ABEI/CoFe2O4/GNs were studied by means of X-ray diffraction, transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The results showed that ABEI and CoFe2O4 MNPs coexisted on the surface of graphene. The magnetic properties of the hybrids were studied by hysteresis loops. The as-synthesized ABEI/CoFe2O4/GNs demonstrated strong magnetic properties. The as-prepared ABEI/CoFe2O4/GNs could be purified by its ferromagnetism to remove excess free molecules. Furthermore, the CL property of the as-prepared ABEI/CoFe2O4/GNs was studied by static injection CL system. It was found that ABEI/CoFe2O4/GNs exhibited excellent CL activity, and the CL intensity of ABEI/CoFe2O4/GNs was about 80 times higher than that of ABEI/GO. The excellent CL efficiency of the as-prepared ABEI/CoFe2O4/GNs was attributed to that CoFe2O4 MNPs immobilized on the surface of graphene catalyzed the decomposition of H2O2 to generate O2·- and HO·,accelerating the CL reaction. The ABEI/CoFe2O4/GNs also demonstrated a good CL stability, and the relative standard deviations of the CL intensity within a day and between days was 2.91% and 2.85%.Besides, the electrochemiluminescence (ECL) properties of ABEI/CoFe2O4/GNs were studied by cyclic voltammetry and pulse potential. It was found that ABEI/CoFe2O4/GNs could produce good ECL in alkaline and near neutral conditions without co-reagents. Two ECL peaks could be observed in ECL-E curve. At the negative potential, O2 was firstly reduced to H2O2, which reacted with ABEI to produce peak ECL-1. At the positive potential, H2O2 was electrochemically oxidized to O2·-,and ABEI was oxidized to ABEI·-, which reacted with O2·- to produce peak ECL-2.Moreover, CoFe2O4 MNPs could catalyze the decomposition of H2O2 to promote the production of active intermediates O2·-and HO·, accelerating the ECL reaction. This work provides a novel graphene-based hybrid with excellent CL/ECL activity and good magnetic performance for the first time. Taking advantage of good magnetic property,unique CL/ECL performance and good stability of ABEI/CoFe2O4/GNs as well as easy-assembly and biocompatibility of graphene, the as-prepared ABEI/CoFe2O4/GNs may be used as an ideal platform for constructing biosensors and bioassays. |
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