Determination of EGFR-overexpressing tumor cells by magnetic gold-decorated graphene oxide nanocomposites based impedance sensor

This work developed an electrochemical impedance spectroscopy (EIS) sensor for detection of EGFR (epidermal growth factor receptor)-overexpressing tumor cell and preliminary estimation of EGFR expression. Here, EGFR antibodies as the specific antibodies for cancer cells were conjugated on magnetic gold-decorated graphene oxide nanocomposites, which were used to capture the EGFR-overexpressing tumor cells. The magnetically responsive tumor cells were enriched and immobilized on a magnetic glassy carbon electrode (mGCE) surface, leading to increased electron-transfer resistance (Ret) utilized for determination of cells and preliminary evaluation of EGFR expression level. This strategy enables the enrichment, fixation and detection of tumor cells to be accomplished in a facile way. An excellent linearity in the range of 2.0 × 102 − 3.0 × 105 cell mL−1 with the detection limit of 152 cell mL−1 for MDA-MB-231 cells was obtained. Investigation on the expression levels of EGFR on various types of cells was conducted. MDA-MB-231 cells showed a distinctly higher EGFR expression, compared with MHCC97-L and L02 cells, providing the possibility for the EGFR-targeted therapy of the tumors. It is expected that the proposed sensor has the potential to be applied for cancer monitoring. A novel Au-GO-MNP-EGFR Ab based impedance sensor, which enables the enrichment, immobilization and detection of tumor cells to be accomplished in a facile way, was developed for sensitive detection of tumor cell and preliminary analysis of epidermal growth factor receptor (EGFR) expression. [Display omitted] •An impedance sensor for detecting tumor cells and analyzing EGFR expression.•EGFR antibodies-coated Au-GO-MNP nanocomposites were used to capture tumor cells.•Magnetically responsive tumor cells were attracted to an mGCE surface.•Enrichment, immobilization and detection of tumor cells are integrated facilely.•EGFR expression on MDA-MB-231 cells is higher than that on L02 or MHCC97-L.