Label-free sensing of genetic sequences with integrated terahertz systems

We present a THz wave based approach for the label-free characterization of genetic material. Time-resolved THz spectroscopic analysis of genetic sequences (polynucleotides) demonstrate a clearly distinct complex refractive index in the THz frequency range as a function of the hybridization state (hybridized/denatured) of the analysed DNA sequences. By monitoring THz signals one can thus infer the binding state of oligo- and polynucleotides, enabling the label-free determination of the genetic composition of polynucleotides. A broadband experimental proof-of-principle in a free-space configuration, as well as a first demonstration of a high-sensitivity integrated approach reaching femtomol detection levels and single base mutation detection capabilities, are presented.