A QCM DNA sensor using extended surface derivatization step and DNA hybridization was reported. The immobilization steps include surface cleaning and activation, first cysteamine, glutaraldehyde, second cysteamine, gold nanoparticle, and thiol modified single stranded DNA (20 T SH-ssDNA) attachments. The size of gold nanoparticles was about 24 nnn. For the prevention of nonspecific and horizontally engages of thiolated ssDNA, a millimolar solution of 6-mercapto-1-hexanol (MCH) was added at room temperature. Immobilized thiolated ssDNA was reacted with complementary ssDNA to study hybridization on surface and hybridization was almost completed with a signal augmentation about 66%. The efficiency of hybridization step is important to show the success of the designed DNA sensor.