Detection of Prostate Cancer's Antigen in Sub-pico Range of Concentration using the Faradaic-mode Electrochemical Impedance Spectroscopy

A biosensing platform for detection of the prostate cancer's `gold standard' marker, the prostate-specific antigen (PSA) is reported. The developed assay combines the application of gold interdigitated microelectrode as the sensing device, together with the electrochemical impedance spectroscopy (EIS) in Faradaic mode of detection for a highly sensitive quantification of PSA binding on the sensor's surface. The binding test revealed the developed assay's capability in detecting the target in sub-pico range of concentration of 10 ng/ml down to 100 pg/ml of PSA in 100 mM phosphate buffered saline (PBS) solution (pH 7.4), covering the clinically accepted PSA threshold value for the `screening' of prostate cancer at 4 ng/ml of PSA.