Fluorescence in sub-10 nm channels with an optical enhancement layer

Area of Science:

• Physical Chemistry
• Nanotechnology
• Biophysics

Background:

• Fluorescence microscopy is vital for micro- and nanofluidic research.
• Sub-10 nm channels exhibit low fluorescence intensity, hindering optical detection.
• Existing methods struggle to analyze phenomena at this nanoscale.

Purpose of the Study:

• To develop a method for enhancing fluorescence signals in sub-10 nm nanochannels.
• To enable sensitive optical imaging and analysis of molecular behavior at the nanoscale.
• To investigate mass transport phenomena in confined environments.

Main Methods:

• Utilized Fabry-Pérot interference with a silicon nitride layer beneath nanochannels.
• Engineered silicon nitride layer thickness to enhance both absorption and emission wavelengths.
• Applied the technique to study binary solution transport in 8 nm nanochannels.

Main Results:

• Achieved a 20-fold enhancement in fluorescence signal intensity.
• Successfully imaged fluorophores in sub-10 nm channels using traditional microscopes.
• Observed molecular separation and reduced diffusivity of Rhodamin B in nanochannels.

Conclusions:

• Fabry-Pérot interference effectively overcomes detection limits in sub-10 nm fluorescence microscopy.
• The method facilitates the study of nanoscale mass transport and biomolecular interactions.
• This technique expands the applicability of fluorescence analysis to unprecedented scales.