Functionalization Of Microfluidic Channels For The Sensing Of Biomolecules And Screening Of Antibacterial Materials

In recent years,microfluidics have attracted more attention as a new type of research technology.The microfluidic chip can not only integrate and react in a small area,but also has less consumables and is very suitable for bedside detection.Therefore,microfluidic devices are widely used in various fields such as biomedicine.With the improvement of living standards,people are paying more and more attention to their own health problems.The early symptoms of many diseases are the abnormal expression of proteins,so protein detection is of great significance in the prevention and treatment of diseases.But the sample size used in clinical practice is small.The low detection concentration and complicated detection methods have brought difficulties to the diagnosis of diseases.Clinically,it is urgent to develop a highly sensitive and small-sized device suitable for on-site analysis to meet the needs of clinical.In the first part of the thesis,the microfluidic chip is composed with polydimethylsiloxane and glass slides by bonding of oxygen plasma,which can combine the sensitivity(change of alignment orientation)and optical characteristicsof liquid crystal molecules to achieve highly sensitive visualization of proteins.Despite the second part of this work is was inspired from the firs one,we found that the concentration gradient of the reactants can be fixed in the microfluidic channel,so we started the second part of this paper.Bacteria are ubiquitous in production and life.Bacteria erode materials and spread diseases which are everywhere in production and life.At the same time,the emergence of drug-resistant bacteria makes antibacterial research face an unprecedented challeng,and how to research and compare the antibacterial ability of various antibacterial materials is the focus of research.In this work,four kinds of quaternized polyethyleneimine(QPEI)by haloalkane with different length of carbon chain was pepared.The samples were characterized by nuclear magnetic,X-ray electron spectroscopy analysis,UV-Vis spectroscopy(UV-Vis),laser scanning confocal microscope(CLSM),fluorescence microscope.The antibacterial activity of the prepared samples was indicated minimal bactericidal concentrations(MB C)values according to the reference methods of Clinical and Laboratory Standards Institute for the determination of MBC of E.coli by tabet method.Then we constructed a gradient surface of quaternized polyethyleneimine by microfluidic technology and studied its antibacterial ability.The results show that the longer the carbon chain is,the better antibacterial activity of the quaternized polyethyleneimine against E.coli has.The originality of this work is to achieve the concentration gradient of quaternary ammonium polyethylenimine by microfluidic technology to compare the antibacterial activity of four kinds of QPEI.This work provides a new idea for studying and comparing material properties.