Fuel-Free Rolosense: Viral Sensing Using Diffusional Particle Tracking

Area of Science:

• Biophysics
• Nanotechnology
• Molecular Diagnostics

Background:

• Conventional viral diagnostics rely on PCR, requiring specialized equipment and time.
• Existing methods often detect viral nucleic acids, not intact infectious virions.

Purpose of the Study:

• To introduce fuel-free Rolosense, a mechanical force-sensing diagnostic platform.
• To demonstrate sensitive and specific detection of intact viral particles.

Main Methods:

• Utilizing aptamer-coated microparticles and Brownian motion on an aptamer-modified surface.
• Detecting viral presence by observing the stalling of microparticle motion due to cross-linking.
• Employing a 3D-printed microscope (Roloscope) for readout.

Main Results:

• Achieved a limit of detection as low as 10^3 copies/mL for SARS-CoV-2 variants (BA.1, BA.5).
• Successfully differentiated SARS-CoV-2 from Influenza A, HCoV OC43, and 229E.
• Demonstrated deep learning analysis of single-particle binding events.

Conclusions:

• Fuel-free Rolosense provides a rapid, sensitive, and specific method for intact virion detection.
• The technology shows potential for point-of-care and home-based viral diagnostics.
• This mechanical transduction strategy offers a complementary alternative to existing diagnostic methods.