A functionalized THz sensor for marker-free DNA analysis.

We report on a novel resonant THz sensor for the label-free analysis of DNA molecules. The sensor allows the direct detection of DNA-probe molecules at functionalized electrodes via hybridization. Subsequent time resolved photoconductive sampling of the THz transmission identifies the binding state between probe and target DNA. Integrating neighbouring sensors on a chip, this technique can be extended to a parallel analysis of multiple DNA sequences. A clearly readable sensor response is obtained with less then 40 fmol of 20-mer single-stranded DNA molecules, indicating at least a sevenfold sensitivity increase compared to previous approaches.