An electronic detection method for DNA molecules based on an extended gate field effect transistor (EGFET) sensing chip has been presented in this paper, which consists of one gold plate electrode for molecule recognition and FET part for signal transduction. The DNA probe was prepared by first immobilization of a thiolated single-stranded oligonucleotide (T1) and then an alkanethiol such as 6-hydroxy-1-hexanethiol (6-HHT) on the gold plate. A fast cyclic voltammetry (FCV) was applied to quantification of DNA molecules by using a cathodic peak around -1.3 V at a electrode reaction, correspondi...