Implications of the Coffee-Ring Effect on Virus Infectivity

Area of Science:

• Virology
• Surface Science
• Biophysics

Background:

• Enveloped viruses like influenza and SARS-CoV-2 pose public health risks.
• Understanding virus survival on fomites is crucial for infection control.
• Bacteriophage Phi6 serves as a model for studying enveloped virus viability.

Purpose of the Study:

• To investigate how droplet evaporation affects enveloped virus viability on polypropylene surfaces.
• To determine the role of culture composition (FBS, BSA, SDS, DMEM) in virus survival.
• To explore the influence of the
• coffee-ring
• effect on virus inactivation.

Main Methods:

• Experiments using bacteriophage Phi6 with varying culture compositions.
• Analysis of droplet evaporation and relative humidity effects.
• Surface-enhanced Raman spectroscopy (SERS) imaging with gold nanoparticles to study solute distribution.
• Correlation of coffee-ring patterns with virus infectivity.

Main Results:

• Virus viability changes were greater than expected based on relative humidity alone.
• Droplet biochemical composition significantly altered virus distribution and survival.
• Lower DMEM and protein concentrations suppressed the coffee-ring effect, irrespective of particle charge.
• A correlation was observed between coffee-ring intensity and virus infectivity.

Conclusions:

• The
• coffee-ring
• effect, driven by solute drying patterns, significantly impacts enveloped virus viability.
• Concentrated coffee rings appear to offer a protective effect against virus inactivation.
• Virus aggregation within concentrated drying rims is a key factor in enhanced survival.