Narrow THz Spectral Signatures Through an RNA Solution in Nanofluidic Channels

Terahertz (THz) transmission measurements are carried out on double-stranded, small-interfering (si)-RNA (20-25 bp) samples suspended in buffer solution and confined to the channels of a nanofluidic chip having channel dimensions ~600 × 500 nm and a pitch of ~1.2 ¿m. The transmission is measured between 800 and 1090 GHz, using a coherent photomixing spectrometer tuned in 0.5 GHz steps. Five narrow spectral signatures are observed that repeated in two successive experiments. Remarkably, the linewidth of some of these features is approximately 10 GHz, making them comparable to if not narrower than the sharpest signatures ever reported at THz frequencies in the solid or liquid states at room temperature.