Study On SERS-pump-free Composite Microfluidic Chip For Trace Detection Of Myocardiac Markers

According to the survey report of the World Health Organization(WHO),Cardiovascular Disease(CVD)has become the leading cause of human death.Creatine Phosphokinase MB Isoform(CK-MB)and high-sensitive cardiac troponin assay(c Tn I)are two main diagnostic markers,so timely and rapid detection of these two markers has become an important reference basis.Point-of-care Testing(POCT)technology can meet such needs.In this context,a new microfluidic composite chip(PDMS-paper-PDMS)is designed and manufactured for the innovation of common microfluidic detection chip.The main research works of this paper are as follows:1.A new type of composite microfluidic chip(PDMS-paper-PDMS)is proposed.First,the schematic diagram of the chip is designed,then the paper chip and the silicon template are made by lithography technology,and the PDMS chip is generated by backward mold on the silicon plate.Finally,the PDMS and the paper chip are sealed with customized double-sided adhesive tape.2.In this paper,the gold sol and silver sol were prepared by using the weak reduction of gold and silver ions in solution with sodium citrate,and seed growth method to make more uniform high concentration of gold sol.Then the state of the particles was observed by transmission electron microscope and the ultraviolet absorption spectrum of the sol was measured.3.Using the weak reducibility of dopamine to synthesize gold ball in situ on paper fiber to make paper gold base.The influence of different concentrations of Tris-HCl buffer solution and different reaction time on the reduction reaction was explored.The ultraviolet absorption spectrum was measured and SERS detection was carried out.4.The sandwich structure(trapping antibody,antigen and labeled antibody)was constructed by enzyme-linked immunosorbent assay(ELISA),and carried out SERS detection of two kinds of myocardial markers(CK-MB,cTnI).