We present a new approach for the label-free characterization of genetic material. Time-resolved THz transmission analysis of polynucleotides demonstrates a strong dependence of the complex refractive index on the binding state (hybridized / denatured) of DNA molecules. By monitoring THz transients one can thus infer the binding state of oligo-and polynucleotides. A broadband experimental demonstration in a free-space configuration is presented. The integration into higher-sensitivity approaches in planar structures, as well as the potential application for next generation gene chips are discussed.
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