| Circulating tumor cells(CTCs)contain a great deal of information of tumor phenotype.Therefore,highly sensitive detection and specific enrichment of CTCs are of intense interest.Herein,a label-free electrochemical impedance spectroscopy cytosensor with effective surface recognition between specific epithelial cell adhesion molecules(Ep CAM)over-expressed on the cell membrane and Ep CAMaptamer was developed for the detection of CTCs.After immobilization of 6-mercapto-1-hexanol(MCH)onto the gold electrode,the capture probe can be directionally inserted in MCH inter-spaces,which can improve the sensitivity of the cytosensor.A wide detection range from 30 to 1×106 cells/m L with a detection limit as low as 10 cells/m Lis reached on the condition of acceptable stability and reproducibility.The cytosensor can easily distinguish CTCs from the real blood sample due to the specific combination of Ep CAM and Ep CAMaptamer.Furthermore,the cytosensor can be reused 8 times and enrich CTCs by Uracil DNA Excision Mix specific cleaving the deoxyuridines(d Us)of the aptamer.The collected CTCs can contribute to further study.Thus,we reported that this cytosensor is a promising technique for the early monitoring and therapy of cancer. |
