Graphene Field Effect Transistors for Breast Cancer Diagnosis

We report the manufacturing of a device to detect the cancer indicative biomarker HER2 (human epidermal growth factor receptor 2) protein. The genetically engineered single chain variable fragment of the HER2 immunoglobulin, with high selectivity towards the HER2 protein, was attached to the graphene field effect transistors (GFETs) using 1-Pyrenebutyric acid N-hydroxysuccinimide ester as the linking molecule. Electron transport properties of the GFETs are measured before and after each chemical alteration. A shift in the current vs. gate voltage curve is observed after the addition of the biomarker that is dependent upon the concentration used. A Hill – Langmuir curve was then fit to the data in order to quantitatively track the response of the devices as a function of the HER2 concentration. Concentrations ranging from the pg/mL to µg/mL could be successfully detected and differentiated.