Microcantilever aptasensor for detecting epithelial tumor marker Mucin 1 and diagnosing human breast carcinoma MCF-7 cells

In this paper, a simple and novel method based on microcantilever for detecting tumor biomarker MUC1 and diagnosing human breast carcinoma MCF-7 cells was proposed. With thiolated aptamers of MUC1 self-assembled on the sensing microcantilever, the targets interact with aptamers resulting in the change of surface stress on the microcantilever. As a result, MUC1 and MCF-7 cells were successfully detected. Among them, the differential deflection of the microcantilever is linear with the logarithm of the MUC1 concentration in the range of 5-500 nM with low detection limit of 0.9 nM. However, for MCF-7 cells, the linear relationship between cantilever deflection and cell concentration ranges from 2.0*10(3) to 5.4*10(4) cells/mL with low detection limits of 213 cells/mL. In the meantime, according to the characteristics of real-time recording the change of microcantilever deflection over time, we have speculated the dynamic process of the binding of MUC1 to the aptamers. This work has confirmed that the aforementioned microcantilever aptasensor could sensitively detect other biomarkers and provide dynamic information of binding, and also could be used to identify tumor cells.