In this work, we have fabricated a porous silicon (PSi) Bragg reflectors microarray using a proper technological process based on photolithography and electrochemical anodization of silicon. Each element of the array is characterized by a diameter of 200 μm. The PSi structures have been used as platform to immobilize label-free DNA probe and a simple optical method has been employed to investigate the interaction between probe-DNA and its complementary target. In order to confirm the specificity of the DNA hybridization, we have also verified that the reaction of probe-DNA with non-complementary DNA did not occur.