Electrochemiluminescence Aptasensor Based on Cascading Amplification of Nicking Endonuclease-Assisted Target Recycling and Rolling Circle Amplifications for Mucin 1 Detection

In this work, a novel and sensitive electrochemiluminescence (ECL) aptasensor for mucin 1 (MUC1) was designed based on cascading amplification of nicking endonuclease-assisted target recycling and rolling circle amplifications (RCA). In the presence of target MUC1, Nt.BbvC I-assisted target recycling process generated massive single-stranded primers which were available for subsequent RCA reactions on the as-prepared sensing interface. With rationally sequence designed, massive long DNA molecules with multiple G-quadruplex units were formed to generate the G-quarduplex/hemin complexes in the presence of hemin, which could enhance the ECL efficiency of luminol-H2O2 system due to its strongly catalytic performance toward the coreactant H2O2. The proposed aptasenor for MUC1 detection showed a limit of detection down to 0.71 fg/mL and a wide linear range from 10 fg/mL to 10 ng/mL with acceptable stability, sensitivity, and possessed promising potential applications in clinical diagnostics. More significantly, it would be available for generalizing the proposed strategy to detect a series of other relative biomarkers.