Carboxyl Graphene Modified PEDOT:PSS Organic Electrochemical Transistor for In-situ Cancer Cells Morphology Detection

Circulating tumor cells in human peripheral blood plays an important role in cancer metastatic. In addition to the size-based and antibody-based cancer cells capture and separation, the electric characterization of cell is also important for rare cells detection, which is fatal in the point-of-care testing. Herein, a solution-gated carboxyl graphene mixed with PEDOT:PSS organic electrochemical transistor (OECT) biosensor for the in-situ detection of cancer cells is reported. Carboxyl graphene was used in this work to modulate the cancer cells morphology, which is differ significantly from the normal blood cells in the rare cancer cells detection. When the concentration of carboxyl graphene mixed in PEDOT:PSS was increased from 0 to 5 mg mL-1, Cancer cell area were increased from 218 μm2 to 530 μm2, respectively. The change of cell morphology can be detected by OECT. The negative charges of cancer cells can induce a positive effect shift of gate voltage, which is about 40 mV for spherical shape of cells. When the cell area increased, the transfer curve was shift to negative effect shift of gate voltage. Therefore, the sensor can realize in-situ detection of cancer cells morphology during the cell capture process, which can be used to identify whether the captured cells were deformable.