Coreactant-FreeDual Amplified Electrochemiluminescent Biosensor Based on ConjugatedPolymer Dots for the Ultrasensitive Detection of MicroRNA

Generally, electrochemiluminescence (ECL) assays are performed in the presence of the coreactant. The addition of the coreactant in the detection solution would make the ECL system lack sufficient stability. In the case of dissolved oxygen as coreactant, the unknown concentration of dissolved O2 would result in an inevitable error and the lack of reproducibility in detection. A coreactant-free ECL assay could overcome above shortcomings, thus is an ideal choice. In this work, a coreactant-free dual amplified electrochemiluminescent (ECL) strategy was constructed for ultra sensitively detecting of microRNA (miRNA). Here, target-catalyzed hairpin assembly and enzyme-triggered DNA walker recycling amplification were integrated to achieve the dual signal amplification. Carboxyl-functionalized poly[9,9-dioctylfluorenyl-2,7-diyl)-Co-1,4-benzo-{2,1’-3}- thiadiazole)](PFBT-COOH) dots were used as luminophore, which displayed a prominent ECL performance without adding any coreactant and removing the dissolved O2. ...