Separation-Free Electrogenerated Chemiluminescence Immunoassay Incorporating Target Assistant Proximity Hybridization and Dynamically Competitive Hybridization of a DNA Signal Probe

-propylamine, the target protein was bounded with two antibodies of the recognition probes and thus induced the sufficient proximity hybridization of DNA3 with DNA1, DNA4 with DNA5-Ru1, and DNA5-Ru1 with DNA1 and the unwinding of the competitor DNA2 with DNA1, and ECL measurement was performed in separation-free format. It was found that the hybridization base number and length of DNA1 and a competing hybridization of DNA5-Ru1 with DNA2 for DNA1 have important effects. The developed ECL method showed a quite low detection limit of 0.4 pg/mL for cTnI, 0.5 pg/mL for cTnT, and 0.5 ng/mL for Myo. The fabricated biosensor exhibited stability and reusability. This work demonstrated that the developed ECL immunoassay is a promising separation-free and flexible strategy for quantitation of multiple proteins using one biosensor.