The Fabrication Of SnO₂@Graphene、α-Ni（OH）₂@3DNCarbon Nanocomposite And Its Performance In Biosensors

Biosensors, a analytical device with bioactive materials as molecular recognition element, has been widely used in various fields of daily life, such as medical treatment and public health, agricultural production, environmental monitoring and so on. As an important component of biosensors, electrochemical bisosensors play an significant role in the physical and chemical analysis area. Comparing with other analysis techniques, it performs prominent electrochemical properties due to the catalytic efficiency and specificity of enzyme. But, it is still a challenge confused researchers how to avoid the denaturation and expose the electroactive center of enzyme during the sensors fabrication process.Nanomaterials with many special properties such as good biocompatibility, high surface area, good thermal and chemical stability, has been considered as an effective method to solve the problem, which can retain the native structure of enzyme, absorb more protein molecules and expose its redox center to realize the electron transfer between the enzyme and the underlying electrode. In the thesis, biocompatible and high conductive SnO2@graphene nanocomposite, and catalytic a-Ni(OH)2@3DNCarbon nanomaterial were successfully synthesiezd. After immobilized on the surface of glassy carbon electrodes, the electrochemical behavior of composite films were researched by cyclic voltammetry, and the electro-catalytic tests to the substance of glucose had been taken. The main contents showed as follows:1. With SnCl4·5H2O and graphene as precursor, SnO2@graphene nanomaterial was synthesized. SAED showed that SnO2nanoparticle presented polycrystalline structure. After fixing the mixture of GOD and SnO2@graphene, Nafion/GOD-SnO2@graphene/GCE was obtained. FT-IR and UV-Vis spectrum indicated the GOD had not changed its conformation in the mixture, which was mainly due to the biocompatible SnO2imported. By cyclic voltammetry, the electrochemical behaviors and catalytic mechanism of GOD was investigated. The amperometric response showed the modified electrode had good catalytic ability to glucose with a wider linear range.2. By annealing natural rose in protective atmosphere,3D Network Carbon (3DNCarbon) was fabricated, which then served as template to synthesize α-Ni(OH)2@3DNCarbon nanocomposite. SEM indicated α-Ni(OH)2nanowire directly grew on the surface of3DNCarbon, which had porous structure. XRD showed the obtained Ni(OH)2was α phase structure. Using cyclic voltammetry, the electrochemical performance of Nafion/α-Ni(OH)2@3DNCarbon/GCE was investigated, and the formal potential was selected for+0.5V by amperometric response. From the catalytic result to glucose, Nafion/α-Ni(OH)2@3DNCarbon/GCE showed a wide linear range (1μM-2.2mM), low limit of detection (1μM).