| Since1909, the first chemical sensor-glassy carbon electrode is created, chemical sensors obtained the fast development. Involving more and more perfect theoretical system of sensors, increasingly wide range of applications and and the adoption of novel methodological approaches. Sensors are so attractive because of their affordable price, compact size, the opportunity that they provide in determining various analytes under special conditions both in the laboratory or in the field; moreover, if necessary, they also make possible remote monitoring. Sensors are used in various branches of industry, medicine, agriculture, ecological monitoring and so on. Since sensors provides a convenient means for the routine analysis method, they have attracted a large number of scientific research enthusiasm. This thesis constructs chemical sensors with azobenzene derivatives or graphene based complexes. The main research contents are as follows:1. Multi-functional azobenzene reversible immobilization of Cytochrome cBifunctional azobenzene derivatives RAzoOC6SH which contains mercaptoalkoxyl and-R (-R=-OH,-NH2,-COOH) were synthesised and the experimental conditions were optimized. The structure of functional Azo monomers were confirmed by ’H-NMR and BC-NMR. The UV-vis spectra results of the test show that the azobenzene derivatives have good response performance of light. One end of the molecular-SH can interact with the gold substrate to fabricate self-assembled (time effects on the growth of self-assembled monolayers was discussed) or applied to dip pen nano-lithography (constructed different nano-structures such as dot/square arrays and letters successfully). the other end with-R has interactions with biological molecules-cytochrome c to realize molecular recognition. Before and after the absorb of fluorescence labeled Cyt c. fluorescence microscope confirmed the synthesized azobenzene derivatives can identify biological molecules. Because Azobenzene derivatives self-assembled layer undergo photon-driven reversible cis trans isomerization, functional groups which combinate with biological molecules from the bare state to embedding shape, which can not have good contact with the biological molecular, in order to achieve light control of biomolecular adsorption and release.2. Cytochrome c modified β-CD functionalized graphene compounds with high molecular recognition capability:synthesis and host-guest inclusion for enhanced electrochemical performanceFirstly, I demonstrate a simple wet-chemical strategy for the preparation of CD-graphene organic-inorganic hybrid nanosheets (GNs-CD) according to the papers, The obtained GNs-CD were characterized by UV-vis spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy. Scanning electron microscopy, and electrochemical impedance spectroscopy, which confirmed that CD had been effectively functionalized on the surface of GNs. Then Cyt c is modified to the GNs-CD by the attraction of opposite charges. The experimental results show that GNs-CD-Cyt c has high molecular recognition capability.and their electrochemical performance has also be enhanced.3. Hollow Nickel oxid-Graphene derivatives in nonenzymatic H2O2sensingThe hollow nickel oxide microspheres (H-NiO) were prepared by remove template method, dip-coating reduction of graphene oxide(GNs) after electrodeposited HNiO onto Au electrode, composite membrane was used for detection of H2O2of different concentration, constructed a new kind of H2O2sensor without enzyme successfully, overcomes the enzyme sensors’unavailable weakness, such as expensive costs, complicated operation and are liable to the environments’influence. Morphology of H-NiO and GNs were characterized by transmission electron microscopy to confirm its struction. In pH=7.5buffer solution, the modified electrode (H-NiO-GNs) has a good electrocatalytic activity to H2O2. Obviously, the GNs enhances the electron transfer rate between the electrode and HNiO. A nonenzymatic film for sensing H2O2is constructed which is based on nanospheres made from hollow nickel oxide particle and graphene. The sensor’s linear detection concentration range from0.1μM to15μM, and the detection limit is0.03μM (S/N=3). The prepared sensor has high sensitivity, good repeatability and good stability... |
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