A simple, specific and “on-off” type MUC1 fluorescence aptasensor based on exosomes for detection of breast cancer

•Tumor-derived exosomes as a novel liquid biopsy biomarker for cancer diagnosis.•MUC-1 is over-expressed on the surface of adenocarcinomas, in particular MCF-7 cells.•MUC-1 is also highly expressed on the surface of exosomes secreted by MCF-7 cells.•MUC-1 aptasensor of “on-off”-type specific detection of tumor exosomes in the blood. Numerous studies have demonstrated tumor-derived exosomes (TEX) as an ideal biomarker for cancer. However, most present exosome detection methods were cumbersome and expensive, simple and specific detection of TEX in the blood still remained a challenging task. To solve the above problem, we found firstly that MUC1 was highly expressed on the surface of exosomes secreted by MCF-7 cells compared to other cells. Here, we designed an “on-off”-type aptasensor based on MUC1 activation on TEX. In the absence of TEX, the aptasensor was “off” state. Once in the presence of TEX, the aptasensor recognized the MUC1 on TEX and then turned “on” state, resulting in emitting a fluorescence signal. We used the aptasensor to detect exosomes derived from MCF-7, MCF-7/ADR, A549, MGC-803 and Hs578Bst cells and blood serum from breast cancer patients and healthy donors. The fluorescence signal value of exosomes from serum in breast cancer patients was markedly higher than healthy donors, which were a significant difference between the two groups (P