DNA hybridization-based detection techniques are widely used in genetics, medicine, and drug discovery. However, the current techniques are usually based on labels and reagents that are time consuming and complex to implement. In this study, we report a label-free DNA sensor based on single-walled carbon nanotube field effect transistor (SWCNTFET) for selective DNA hybridization detection of H5N1 virus. A network of single-walled carbon nanotubes (SWCNTs) acts as the conductor channel. ProbeDNA sequences were adsorbed onto SWCNTs. The developed DNA sensor can effectively detect full-complementary DNA with concentration as low as 1.25 pM. The sensitivity of the DNA sensor reached approximately 0.28 nM/nA. The effect of the parameters, including DNA probe concentration, its complementary concentration, mismatched sequence, and hybridization time, on the sensor response was also studied. The results showed the potential application of the DNA sensor for medical, environmental, and epidemic detection. (C) 2013 Elsevier B. V. All rights reserved.