Immunogold–silver staining-on-a-chip biosensor based on cross-flow chromatography

摘要: Immunogold-silver staining (IGSS) was adopted in cross-flow chromatographic analysis which immunological reactions and silver intensification were sequentially conducted the vertical horizontal directions, respectively. Factors controlling performance, except substrate solution, optimized to increase signal-to-background ratio measurements of cardiac troponin I as a model analyte. In generating signal, size colloidal gold catalyst critical; smallest (5-nm diameter) selected range yielded highest colorimetric signal. To maintain low background, two processes, blocking remaining surfaces membrane after antibody immobilization washing residual tracer reaction, necessary. Self-nucleation ions also caused background signal controlled some degree by decreasing hydrodynamic force that arose when solution supplied direction. Finally, new chip (IGSS-on-a-chip; IOC) allowed for convenient, efficient IGSS produced injection molding plastic. This method enhanced detection capability 51-fold compared conventional rapid test kit using 30nm-sized tracer. The IOC biosensor results showed yield via cross flow reaction 19% higher than traditional incubation.