Detecting DNA by field effect transistor arrays

We present electronics approach for the detection of unlabeled DNA. The biopolymers are immobilized on an array of field effect transistors integrated in silicon. Local immobilization to part of the array is achieved by direct deposition with a microspotting device and specific hybridization between complementary DNA oligonucleotides. The current voltage characteristic of the transistors is measured with the sample surface in contact with an aqueous solution. It is shown that both DNA adsorption and hybridization induce sizeable variations in the current-voltage characteristics