The PGEs were immersed into the vials containing 110 of 16 dsDNA solution. The electrodes were kept in these vials for 7.5 min followed by passive adsorption proceduce and washed into ABS (pH=4.8) foe 5 s to inhibit unspecific binding. Then, dsDNA immobilized PGEs were immersed into the vials containing 110 of 0.5 TPT solution by using different interaction times and washed into PBS (pH=7.4) for 5 s