Development Of Microfluidicchips-based Sample Preparation For Bioanalysis And Relatedmicro Devices

With the rapid development of our aerospace industry, the study of space science isgoing constant deepening. Space life science is an important component part of spacescience, and also a hot field in global world. To explore the living organisms’ special statesand changes in space environment, demands of popper analytical instruments for lifescience in space are proposed. The analytical instruments which are based on microfluidicchips have the features of small volume, low energy consumption, easily integration andless consumption of samples, meanwhile, become the first choice of spatial analyticalinstruments.The research objects in biology experiments are broad, and most of thepractical samples are complex. A series of preprocessors need to be done before analysis,however, most cannot be accomplished in the space environment. The features ofmicrofluidic chip make it becomes the most important means of preprocessors. Initially, itsmicrosize typically matches with bio-samples and it can dispose with definitely lowsamples. Subsequently, the micro-scale and controllable fluid provide large connect areabetween samples and reactant or other different samples, which raise the reaction effect andshorten the preparation time. Finally, it can be integrated into the whole instrument, andtypically meets the requirement of space science research.The study of preprocessor in microfluidic chip can not only service for the spaceexperiments, but also an alternative and supplementary method for conventionalexperiments in lab. At the same time, it can improve the processing efficiency of thesamples and reduce the sample loss and experimental error during time periods.This paper relies on the microfluidic chip platform to study the samples pretreatmentof Deoxyribonucleic acid (DNA) and protein. Various chips and micro-instruments are alsoproposed during the research process. The main contents include:(1) Making the whole molding procedure of PPolydimethylsiloxane (PDMS) localizedand obtaining series technological parameters which vastly improved the success rate. Byusing this technology, the success rate reached percentage of over80%and frequency metthe demand of experimental study. The success rate of fabricating chip achieved100%.(2) Developing an extraction chip based on recycle structure and double laminar.Rhodamine-B was successfully extracted form water and the result showed approximately100%efficiency. The subsequent experiments were carried out by dealing with DNA samples and the whole genome was extracted from blood cells.(3) Providing a DNA extraction chip utilized paramagnetic particle method. And atfirst, the chip was used to study and acquire droplet. Combined with magnetic shelf usingparamagnetic particle method, the work of DNA extraction was developed. The wholegenome was separated from lymphocyte which, the result was comparable to conventionalkit.(4) By using pre-existing trypsin aptamers, zymolytic chip was proposed as a methodfor protein samples preprocessor. The chip chose PDMS as fabrication material, withmultiple designs and improvement, and the final design was picked as a microchannel withmicrocolumn array. Partial assistant instruments were also presented before on-lineenzymolysis.During the fabrication procedure, based on existing enzyme reactor with silica gelbeads, the filter results showed that trypsin was immobilized by fluid passed through. Thefinal method of immobilization was first use1%3-aminopropytriethoxysilane(APTES) tomodify the microchannel and then glutaraldehyde crosslinking was taken out to immobilizethe trypsin aptamers under the condition of carbonate buffer solution with pH9.2.Ultimately, aptamers fixed with trypsin were obtained under pH8.0condition. Theoretically,the immobilized trypsin reached a maximum of0.3μg inside the chip.Enymzatic hydrolysis of different standard proteins was assessed by offline testing.BSA could be hydrolyzed successfully in less than3seconds. A preferable result might be a10mm channel with sample injection rate of10μL/min. We also tested the practical samples.And a chip enzyme reactor/HPLC/MS platform was established to deal with sample onlinepreprocessor.(5) Developing an easy controllable air pump serviced for microfluidic chip. Thedesign, fabrication, debugging and application were all done independently. By controllingthe fluid movement though the switch of pneumatic microvalve, the instrument could besuccessfully used in PDMS microvalve chips which also met the experimental demands andfilled in the blanks in laboratory.(6) Participating multiple researches and developments of space analytical instruments,including gene amplification, nucleic acid analysis and cell co-culture. The spacemicrofluidic chip instrument research is a huge project, and this paper contains a part of it,including the ground test of gene amplification instrument, the whole equipment design,component design and principle prototype of nucleic acid analysis/cell co-culture instruments and detection instruments. In the team joint efforts, chip gene amplificationinstrument was successfully carried out and obtained space life science data. Principleprototypes of the other two instruments were almost done.In a word, as a tool for sample preparation in chip, withdrawal of DNA might be flator a little less compared with conventional method, but the chip has the potential ofintegrating amplification and analysis modules. Though the results show a bit less effectsthan conventional enzymolysis, it shows less time consuming which provides an efficientpreprocessor for proteomics analysis. In conclusion, the utilization of preprocessor forbiomacromolecule in chip can deal with samples with absolutely low content. Theadvantages are less time consuming and procedure with a good application foreground.