Electrochemical Assay of GSTP1-related DNA Sequence for Prostate Cancer Screening

A label free detection scheme is developed for a short GTSP-1 (Hypermethylation of glutathione-S-transferase p gene) related DNA sequence (27 mer) based on modified PolyPyrrole (PPy) films deposited at a microelectrode surface. The positively charged PolyPyrrole films are modified by addition of negative charge through phosphoric acid groups of complementary strands to PPy-pTPTC3-PO3H2-Mg2+/ probe DNA to create an electrostatic barrier for the incoming anions that influences the kinetics, as noted by cyclic voltammetry (CV). The hypermethylated sequences of GSTP-1 gene are prevalent in prostate cancer patients and this DNA hybridization can be diagnosed from changes in the cyclic voltammogram shape using this assay technique, which will be useful for early detection of the cancer.