Construction Of Microfluidic Devices Based On The Micro/nanostructured Separation Materials And Their Application In The Separation Of Proteins

In the post-genome era, proteomics is a key task in life science and the separation of proteins is the foundation of proteomics. However, traditional protein separation means couldn’t meet the requirement of high efficient and high through-put protein separation. It is very necessary to develop a novel protein separation mean. If microfluidic technology with the advantages of miniaturization, integration, automation could be applied to separation of protein, high efficient and high through-put protein separation is expected to be realized. To date, transition metal affinity chromatography has been widely applied to various proteins. And the integration of transition metal affinity chromatography into microfluidic technology has drawn great attention gradually. This thesis focused upon the construction of micro/nanostructured transition metal compounds and their combination with microfluidic technology. And the application of transition metal compounds-based microfluidic device in fields of the separation of high-abundant protein and the enrichment of low-abundant peptide was systematically investigated.Three kinds of micro/nanostructured NiO arrays were constructed in confined microchannels via microfluidic chemical fabrication under the condition of different concentration of reactants. The microfluidic devices were constructed on the basis of NiO arrays modified capillary microchannel, and Ni O nanosheet arrays-based microfluidic device exhibited good absorption ability towards bovine hemoglobin(BHb) and bovine serum albumin(BSA) under the conditions of certain pH and ionic strength. And the NiO nanosheet arrays-based microfluidic device could almost absorb all the target protein when the protein solution(0.5 mg mL-1) resided in the microchannnel for 120 s without separation. Moreover, the microfluidic device exhibited good selective absorption ability towards BHb from protein mixture under the conditions of certain pH and ionic strength, and it could selectively absorb human hemoglobin(HHb) from 500-fold human blood.Ultralong rhombus-like Zn(OH)F nanorod array(the length of arrays was about 60 μm) were constructed in confined microchannels via microfluidic chemical fabrication. The microfluidic devices were constructed on the basis of rhombus-like Zn(OH)F nanorod array modified capillary microchannel. The effect of pH and ionic strength on the absorption ability of microfluidic device was investigated, and the microfluidic device exhibited the best absorption ability towards lysozyme(Lyz) and BHb under certain ionic strength. The microfluidic device could almost absorb Lyz and BHb separately when the protein solution(0.5 mg m L-1) resided in the microchannnel for 14 min and 80 s. In addition, Lyz absorption capacity and BHb absorption capacity of the microfluidic device was 3700 and 63094 g m-3, which was 10 times than that of NiO nanosheet arrays-based microfluidic device. The microfluidic device exhibited good selective absorption ability for Lyz and BHb, and it also could selectively absorb Lyz from egg white and HHb from human blood.Based on the construction of Zn(OH)F arrays, the effects of the molar ratio of Zn to F and different fluorides on the morphology of ZnO/Zn(OH)F arrays were investigated. ZnO/Zn(OH)F nanofiber array and three-dimensional network were constructed. The microfluidic devices were constructed on the basis of ZnO/Zn(OH)F array modified capillary microchannel. In the photocatalytic application, the nanofiber array-based microfluidic devices could almost photodegrade methylene blue solution(5 ppm) as the residence time was 50 s; based on the unique advantage of micro/nanostructure, in the application of bio-separation, the nanofiber array-based microfluidic devices could also absorb all the BHb(0.5 mg m L-1) as the residence time was 50 s. The photocatalysis property could be applied to improve the recycling performance of microfluidic device. After 50 min of ultraviolet light irradiation, the microfluidic device could restore the protein absorption ability fully. Compared with the overnight soaking with PBS buffer, the photocatalytic treatment improved the recycling performance of microfluidic device dramatically. After 10 cycles, ZnO/Zn(OH)F-based microfluidic device could still absorb over 90 % BHb(0.5 mg mL-1) and exhibited outstanding recycling performance.Ni(OH)2 three-dimensional network was successfully constructed through the modification of Ni(OH)2 on the ZnO/Zn(OH)F three-dimensional network. The microfluidic device was constructed on the basis of Ni(OH)2 three-dimensional network modified capillary microchannel and exhibited outstanding protein absorption ability. The microfluidic device could absorb all the BHb(0.5 mg m L-1) as the residence time was 25 s. And BHb absorption capacity of the microfluidic device was 114450 g m-3, which increased by 30 % than that of ZnO/Zn(OH)F-based microfluidic device. The recycling performance of microfluidic device was also very good, and the microfluidic device could absorb about 90 % BHb(0.5 mg m L-1) after 10 cycles. Moreover,the microfluidic device could selectively absorb all the HHb from 100 fold-diuted human blood. In conclusion, Ni(OH)2 three-dimensional network-based microfluidic device exhibits high-efficiency and high throughput absorption ability toward histidine-rich protein.TiO2-ZrO2 inverse opal films on the glass slide were constructed through evaporation-induced self-assembly method and sol-gel method, and the inverse opal films possessed large specific surface area. And the distributions of Ti, Zr and O were all uniform in the films. The microfluidic devices were constructed on the basis of TiO2-ZrO2 inverse opal films. And the inverse opal-based microfluidic device exhibited well enrichment ability towards mono-phosphopeptides and multi-phosphopeptides when the residence time was 30 s. We also found that the phosphopeptides enrichment ability of microfluidic device depended on the micro/nanostructure of inverse opal films, and TiO2-ZrO2-270-based microfluidic device exhibited better enrichment performance.