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.

[1]  S. Brueck,et al.  DNA transport in hierarchically-structured colloidal-nanoparticle porous-wall nanochannels. , 2008, Nano letters (Print).

[2]  Steven R. J. Brueck,et al.  Optical and Interferometric Lithography - Nanotechnology Enablers , 2005, Proceedings of the IEEE.

[3]  E. Heilweil,et al.  Pulsed terahertz spectroscopy of DNA, bovine serum albumin and collagen between 0.1 and 2.0 THz , 2000 .

[4]  H. Craighead,et al.  Separation of long DNA molecules in a microfabricated entropic trap array. , 2000, Science.

[5]  S S Chan,et al.  Sorting by diffusion: an asymmetric obstacle course for continuous molecular separation. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[6]  J L Hesler,et al.  Submillimeter-wave phonon modes in DNA macromolecules. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[7]  B. Gelmont,et al.  Submillimeter-wave fourier transform spectroscopy of biological macromolecules , 2002 .

[8]  Fabrication of enclosed nanochannels using silica nanoparticles , 2005 .

[9]  Arthur C. Gossard,et al.  Room temperature, THz photomixing sweep oscillator and its application to spectroscopic transmission through organic materials , 2004 .

[10]  Harold G. Craighead,et al.  Entropic trapping and sieving of long DNA molecules in a nanofluidic channel , 1999 .

[11]  R. Austin,et al.  Excited-state lifetimes of far-infrared collective modes in proteins. , 2001, Physical review letters.

[12]  J. E. Bjarnason,et al.  Sensitivity measurement and analysis of an ErAs:GaAs coherent photomixing transceiver , 2005 .

[13]  A. Bosserhoff,et al.  Label-Free Probing of the Binding State of DNA by Time-Domain Terahertz Sensing , 2000 .

[14]  Ronald T. Logan,et al.  A coherent frequency-domain THz spectrometer with a signal-to-noise ratio of 60 dB at 1 THz , 2008, SPIE Defense + Commercial Sensing.

[15]  Mario Cabodi,et al.  Continuous separation of biomolecules by the laterally asymmetric diffusion array with out‐of‐plane sample injection , 2002, Electrophoresis.

[16]  Michael J. O'Brien,et al.  Fabrication of an integrated nanofluidic chip using interferometric lithography , 2003 .

[17]  S. Brueck,et al.  Electrokinetic molecular separation in nanoscale fluidic channels. , 2005, Lab on a chip.

[18]  Pascal Silberzan,et al.  From the Cover: The dynamics of genomic-length DNA molecules in 100-nm channels. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[19]  Anna M. Fedor,et al.  On the strong and narrow absorption signature in lactose at 0.53THz , 2007 .

[20]  W. DiNatale,et al.  Generation and detection of coherent terahertz waves using two photomixers , 1998 .

[21]  David F. Plusquellic,et al.  Continuous-wave terahertz spectroscopy of biotin: vibrational anharmonicity in the far-infrared , 2004 .