Electrochemical biosensors have a key importance in many areas including clinical, biological, pharmaceutical, forensic, environmental and agricultural applications. They have the advantages of rapid, easy and low cost preparation allowing the localization of biocompound on electrodes of any size with independence of sample turbidity, high sensitivity and high selectivity. Electrochemical devices have attracted considerable interest in the development of DNA hybridization biosensors. They rely on the conversion of hybridization event into a direct electrochemical signal. Many efforts have been carried out in the detection of DNA hybridization for improving the stability, reproducibility and sensitivity.