Single-Molecule Sizing through Nanocavity Confinement

Area of Science:

• Nanotechnology
• Biophysics
• Analytical Chemistry

Background:

• Accurate sizing of nanoscale particles and biomolecules is crucial for fields like nanobiotechnology and clinical diagnostics.
• Existing sizing methods can be complex or lack single-molecule resolution.

Purpose of the Study:

• To develop a novel, rapid, and quantitative method for sizing nanoscale particles and single biomolecules in solution.
• To establish nanocavity diffusional sizing (NDS) as a viable technique for particle characterization.

Main Methods:

• Theoretical modeling and simulations to understand particle diffusion within nanocavities.
• Experimental demonstration using single-molecule confocal microscopy to measure particle residence times.
• Utilizing nanofluidic cavities for controlled confinement of particles.

Main Results:

• Particle residence times in nanocavities correlate with their diffusion coefficients and thus their sizes.
• Demonstrated linear scaling of residence times with the size of colloids, protein aggregates, and DNA oligonucleotides.
• NDS provides quantitative size measurements at the single-molecule level.

Conclusions:

• Nanocavity diffusional sizing (NDS) is a novel optofluidic approach for precise particle sizing.
• The method is applicable to a range of nanoscale entities, including biomolecules.
• NDS holds significant potential for applications in nanobiotechnology, biophysics, and diagnostics.