Research On Detection Of Cardiac Troponin By Nanospheres

Acute myocardial infarction caused by persistent and severe myocardial ischemia caused by acute myocardial necrosis is a relatively common clinical disease,its main features are acute onset,dangerous condition,and great harm,timely diagnosis and effective treatment is the main measure to reduce the mortality and disability of the disease.The CBA detection method,which is more popular nowadays,makes full use of the advantages of multi-signal detection and liquid-phase microspheres in flow cytometry,such as large specific surface area,less nonspecific reaction,and simple operation.The carrier used is polystyrene microspheres.We first synthesized the carboxylated polystyrene microspheres with uniform particle size using the dispersion polymerization method,studied the activity of the surface carboxyl groups,and the saturating amount of IgG-coupled proteins,and made a simple detection experiment.The amount of protein saturation of the experimental polystyrene microspheres was1.56×10~7(0.1 mg)of polystyrene microspheres capable of coupling 600 ng of IgG.Based on this experimental result,we conjugated 500ng of cardiac troponin T to 20μL magnetic microspheres(1.074×10~7)to obtain the functionalized microspheres used in this experiment.Using magnetic microspheres as a carrier,we have developed a simple,low-reagent loss,high-sensitivity assay for cardiac troponin.This method makes full use of the proper size,large specific surface area,high dispersibility and superparamagnetism of magnetic microspheres.The carboxyl group of the cardiac-specific troponin coupled to the surface of the magnetic microsphere in the form of a covalent bond constitutes the functionalized microspheres we use with covalty bond troponin T,surface-functionalized magnetic microspheres,and excess antibodies were sequentially added into the 1.5 mL EP tube.Consequently,the cardiac troponins T in the serum,the cardiac troponins T on the surface of the functionalized microspheres were competing for binding to the immune response domain of antibodies.After magnetic washing,the primary antibody on the surface of the microspheres labeled with a fluorescent secondary antibody was detected on the machine.Therefore,when the level of cardiac troponin in the serum is higher,the signal detected by the instrument is weaker,and the lower the level of cardiactroponin in the serum,the stronger the signal detected by the flow cytometer.In this study,the established standard curve has a fit of R~2=0.99971 and a detection limit of 0.5 to 100ng/mL.We can use the established method for the detection of cardiac troponin to couple different biological probes on the surface of different magnetically encoded magnetic microspheres and apply it to the simultaneous quantification of multiple cytokines such as cTnI,CK-MB,and MYO.Immunogenic reactions were performed in a simple EP tube to quickly and accurately diagnose acute myocardial infarction.