Enzyme-free Target Recycling and Double-Output Amplification System for Electrochemiluminescent Assay of Mucin 1 with MoS₂ Nanoflowers as Co-reaction Accelerator

In this work, a sensitive electrochemiluminescent assay of mucin 1 (MUC1) was developed with the advantages of target recycling amplification strategy and effective MoS2 nanoflower (MoS2 NF)-based signal probe. Briefly, the target MUC1 triggered enzyme-free recycling and a double-output amplification process was executed to acquire masses of single-stranded DNA as a mimic target, which further participated in the catalytic hairpin assembly process for signal amplification. Meanwhile, MoS2 NFs were prepared as an effective co-reaction accelerator, which not only possessed excellent catalytic performance for H2O2 decomposition to largely enhance the luminous intensity of N-(aminobutyl)-N-(ethylisoluminol) (ABEI)-H2O2 electrochemiluminescence system but also offered a desirable platform for ABEI-functionalized Ag nanoparticles (ABEI–Ag complexes) loading via Ag–S binding. The experimental results showed the proposed aptasensor had a good linear relationship in the range of 1 fg/mL to 10 ng/mL for MUC1 detection and the limit of detection was 0.58 fg/mL (S/N = 3). In addition, the aptasensor had nice stability and selectivity and huge potential to be applied in clinical research.