Highly sensitive α-hemolysin nanopore detection of MUC1 based on 3D DNA walker

Mucin 1(MUC1) is an effective marker of breast cancer, so it is of great significance to develop a simple, sensitive and highly selective MUC1 detection sensor. Herein, we constructed a label-free nanopore biosensor for rapid and highly sensitive detection of MUC1. The presence of MUC1 triggered the modification of the DNAzyme walking chain on the surface of Fe₃O₄ nanoparticles and separation from the aptamer. In the presence of Zn²⁺, DNAzyme catalyzed hydrolytic cleavage of the hairpin substrate at the scissile rA. The DNAzyme was divided into two fragments and ssDNA was released. ssDNA products from the hairpin substrate can generate a current blocking signal during α-hemolysin nanopore testing. The frequency of signature events showed a linear response toward the concentration of MUC1 in the range of 0.01 nM-100 nM. The sensing system also exhibited high selectivity against other protein and can be used for the detection of real sample.