zero-mode waveguide is an
optical waveguide that guides light energy into a volume that is small in all dimensions compared to the
wavelength of the light.
Zero-mode waveguides have been developed for rapid parallel sensing of
zeptolitre sample volumes, as applied to
gene sequencing Gene Sequencing may refer to:
* DNA sequencing
* or a comprehensive variant of it: Whole genome sequencing
Whole genome sequencing (WGS), also known as full genome sequencing, complete genome sequencing, or entire genome sequencing, is the pro ...
, by
Pacific Biosciences (previously named Nanofluidics, Inc.)
A waveguide operated at frequencies lower than its
cutoff frequency (wavelengths longer than its
cutoff wavelength) and used as a precision
attenuator is also known as a "waveguide below-cutoff attenuator."
The zero-mode waveguide is made possible by creating circular or rectangular nanoapertures using
focused ion beam on an aluminium layer.
The zero-mode waveguide can also enhance fluorescence signals due to surface plasmon generated at metal-dielectric interfaces. Due to surface plasmon generation field is localized and enhanced as well as it changes the LDOS inside the cavity which leads to increase in Purcell Factor of analyte molecules inside the zero-mode waveguide
The zero-mode waveguide is very useful for Ultraviolet Auto-fluorescence spectroscopy on tryptophan-carrying proteins like beta-galactosidase
with further modification of the zero-mode waveguide with a conical reflector its possible to study the dynamic process of smaller proteins like streptavidin with 24 tryptophan.
,
The modified zero-mode waveguide with a conical reflector can be further optimized to enhance the Signal-to-noise ratio and reach the ultimate sensitivity of single tryptophan proteins like TNase.
See also
*
Single molecule real-time sequencing
References
Biophysics
Physical optics
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