Research On The On-site Protein Detection Systems Based On Microfluidics And Opto-electronic Sensing

Protein is the basis of all creatures,one of the most important components of cells,the undertaker of vital activities.The protein detection,especially the specific detection of the proteins as biomarkers,has found wide application in many areas such as disease diagnosis,food safety and etc.Moreover,it will be critical to a society,a country even the human beings to accomplish on-site/POC(point of care)protein detection when fatal pandemics break such as bird flu,zika and etc.Thus,POC relative methods,technologies,protocols and etc.to protein detection have always been the spotlight of researchers all over the world.To find out the reasons that current protein detection can't be carried out on-site,lots of domestic and international research work were studied.And it could be summarized that there are at least these reasons: It is too long to perform a protein detection while it would take several hours even days;The protocols are complicated and the operators need to be trained well beforehand;The places for the detections have to be professional enough like a laboratory and the cost of detections is expensive.So to solve the problems listed above,this research has done the work as follows:?Based on the meaning of protein and protein detection.Some of the most common methods for protein detection were studied and their problems were given.Meanwhile,the interest of all the researchers was studied to help accomplish the goal of this work,namely,based on the microfluidic,opto-electronic sensing and detection technology to realize an easy-use and low-cost POC(point of care)protein detection system with high sensitivity.?Two schemes of POC protein detection systems based on micro-particles manipulation and opto-electronic sensing were designed.And the following principles,methods and key technologies were studied: The principle of protein detection based on immunoadsorption;The fabrication of a microfluidic chip and its channels using silicon wafer,PDMS and the process of “soft lithography”;The principle and methods of manipulating particles based on multiple AC electrokinetic effects;The principle and method of LED induced fluorescence;The impedimedance measurement of electrodes in the liquid.?According to the research on the manipulation of micro-particles using AC electrokinetic effects and the method of fluorescence induced by LED,an acceleration of protein detection mechanism that to employ a swirl-like flow induced by AC electrothermal effect was designed.And a portable fluorescence sensing based protein detection system was designed.This is the first actively guide the target proteins instead of waiting for its passive diffusion.?According to the research on the manipulation of micro-particles using AC electrokinetic effects and the method of the principle and method for impedance measurement of elcctrodes in liquid,an acceleration of protein detection mechanism that to use dielectrophoresis was designed.A portable impedimetric sensing POC protein detection system was designed.This system is easy to use,rapid and capable of detecting protein on-site.?The detection of protein IgG,D-dimer and Johney's Disease was carried out by using the microfluidic based fluorescent POC protein detection sytem and the microfluidic based impedimetric POC protein detection sytem respectively.The results showed that the give two POC protein detection systems with their protocols could complete every assay rapidly,precisely and effectively.Aiming at the realization of on-site protein detection.A novel method of manipulating the protein by using the AC electrokinetic effects was given.This method could actively guide the target proteins instead of its passive diffusion.The designed LED induced fluorescence POC protein detection system and relative protocol was recognized by the peers as the first to use active guidance of analytes diffusion to nanoscale sensors,which previously had been purely based on thermodynamic diffusion in a flow through channel.The designed impedance POC protein detection system and relative protocol were capable of completing protein detection within 1 min with an LOD of 10 ng/mL under 1 dollar per assay in the world.The succesful born of this system had attracted lots of interests of media and companies in the north America like Wall Street Journal,American Broadcast Company,Gizmag,Pfizer and etc.