Preparation Of Self-Organized Nanoporous Materials And Study Of Their Application In The Construction Of Nonenzymatic Glucose Sensor And Purification Of Proteins

Nanomaterials have attracted considerable attention in the field of nanotechnology research. Because their scale between atom clusters and macroscopic matters, it exhibits several peculiar characteristics, For example, the quantum size effect, surfece effect, small size effect, the macroscopic quantum tunnel effect, and so on. Some nanomaterials have special mechanical, electrical, magnetic, optical, thermal and catalytic characters. Compared with other nanomaterials, nanoporous materials have attacted lots of interest due to their large surface area, porous structure, high surface reactivity, biocompatibility, strong adsorption capacity and other characteristics. Thus, we study the application of nano-materials in the construction of biosensors and protein separation in this paper.The first chapter gives a brief describe for the concept, properties and applications of nanomaterials, while the preparation and application of titania nanotubes as well as nanoporous materials are described in detail. The applications of nanomaterials in biosensors and protein separation are also discussed in the text. In the end, we give a brief summary for the significance of this topic.The second chapter mainly studies the preparation of nanoporous NiO/TiO2 layers and their application in nonenzymatic glucose sensing. A highly ordered nanoporous NiTi oxide layer was fabricated on Ti alloys with high Ni contents (50.6 at.%) by a combination of self-organizing anodization at low temperature and subsequent selective etching in H2O2. The key for successful formation of such layers was to sufficiently suppress the dissolve of NiO by applying lower temperature during anodization. The resulting nanoporous structure was connected and well-adhered, which exhibited a much higher electrochemical cycling stability in 0.1 M NaOH. Without further surface modification or the use of polymer binders, this NiO/TiO2 layer could be used as a low-cost, stable andsensitive platform in non-enzymatic glucose sensing. For glucose sensing, the calibration plot was linear over a broad concentration range of 0.005-12.0 mmol L-1 with a correlation coefficient of 0.999, a sensitivity of 252μA mM-1 cm-2. Considering the detection limit as 3 time of the noise level, the detection limit for the proposed electrode was detemined as 1.0μmol L-1.The third chapter mainly studies the preparation of TiO2 nanopipes and the exploration of its application in separation and purification of human serum albumin. First, we prepared TiNTs by anodie oxidization and removed the TiNT layer from the metallic substrate. By etching with HF, the bottom of the nanotube was opened. In this work, we employ one-step method to synthesis carbon-coated TiO2 (C/TiO2) nanopipes by pyrolysising the carbon precursors adsorbed on the TiO2 nanotube wall.The as-formed C/TiO2 nanopipes were applied in the separation and purification of human serum albumin (HSA). The conditions for adsorption and elution have been optimized. In additon, the C/TiO2 nanopipes have be used in the purification of HSA in human blood. The results demonstrate that the as-prepared C/TiO2 nanopipes have satisfied biocompatibility and the adsorption/desorption abilities in separation and purification of HSA. Under the optimized conditions, the adsorption efficiency reaches 75%～80% and the elution efficiency is over 80%. The HSA molecules keep their original conformations and activities. Moreover, by utilizing the photocatalytical property of TiO2, the surface of C/TiO2 nanopipes can be further cleaned after separation and purification expeiments via UV light irradiation.