A novel impedimetric disposable immunosensor for rapid detection of a potential cancer biomarker

A specific and sensitive biosensor was developed successfully for quantitative detection of human epidermal growth factor receptor by electrochemical impedance spectroscopy. Anti-human epidermal growth factor receptor antibody was covalently immobilized onto a screen-printed carbon electrode modified with a carbon nanotube. Immobilization steps were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). After human epidermal growth factor receptor ligates with anti-human epidermal growth factor receptor immobilized onto an electrode surface, charge transfer resistance changes considerably. This electrochemical response was correlated with human epidermal growth factor receptor concentration. Under optimal conditions, the proposed biosensor could detect human epidermal growth factor receptor 2 fg/mL with a linear range from 2 to 14 fg/mL, showing high sensitivity. Kramers–Kronig Transform was performed on the experimental impedance data. Meanwhile, in a biosensor system, the Single Frequency Impedance technique was first used for characterization of interaction between human epidermal growth factor receptor and anti-human epidermal growth factor receptor. Eventually, the proposed biosensor was applied to artificial serum samples spiked with human epidermal growth factor receptor.