The device featured a gold electrode array with tunable sensor surface areas, which were modified with a capture antibody specific for Epithelial cell adhesion molecule (EpCAM, anti-EpCAM antibody) to selectively count prostate cancer cells using the differential pulse voltammetric response in the presence of [Fe(CN)6]3−/4−. The gene discussed is EPCAM; the disease is prostate carcinoma.