Application of Ethyl Green as Electroactive Indicator in Genosensors and Investigation of its Interaction with DNA

A new electrochemical DNA hybridization biosensor based on carbon paste electrode (CPE) and ethyl green (EG) is described. The interaction of EG and DNA is investigated in the solution and at the surface of the electrode. The results of electrochemical and spectroscopic studies indicate electrostatic interaction mode between DNA and EG. Hybridization event between the probe and its complementary sequence is investigated by square wave voltammetry of EG accumulated on the CPE. EG displays different signals in the interaction to ssDNA and dsDNA and variation in the EG signal represents the extent of hybridization at the electrode surface. The effects of some experimental variables on the performance of the biosensor are studied and optimized conditions are suggested. The selectivity of the biosensor is studied using some noncomplementary oligonucleotides. Under optimized experimental conditions, limit of detection is calculated 2.0×10-10 M.