Electrochemical assay for detection of circulating tumor cells based on LiFePO4 as electrochemical probe

In this study, we reported an electrochemical assay for detecting circulating tumor cells (CTCs) in whole blood. Breast cancer cell MCF-7 was chosen as a model for study. Fe3O4 magnetic nanospheres (MNs) modified with anti-epithelial cell adhesion molecule (EpCAM) antibody were utilized to capture MCF-7 from samples and gold nanoparticles modified LiFePO4 (LiFePO4/Au) particles were chosen as electro-chemical label. Aptamer can be linked onto LiFePO4/Au via Au-S bond, and then the LiFePO4/Au-aptamer complex can specifically bind to the MUC1 protein that is over-expressed on the cell surface of MCF-7. Electrochemical signals are generated by the reaction of phosphate in LiFePO4 with molybdate to form redox molybdophosphate. The utilization of LiFePO4 for signal probe may expand the application of LiFePO4 in biosensing fields. (C) 2020 Elsevier B.V. All rights reserved.