Ultrasensitive detection of intact SARS-CoV-2 particles in complex biofluids using microfluidic affinity capture

Area of Science:

• Biomedical Engineering
• Virology
• Microfluidics

Background:

• Detecting viruses like SARS-CoV-2 in complex biofluids is challenging due to interfering biomolecules.
• Accurate viral load measurement is crucial for effective disease management and monitoring treatment efficacy.

Purpose of the Study:

• To develop an affinity-based microfluidic device for the specific capture and detection of intact severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
• To enable ultrasensitive quantification of viral load in various human biofluids.

Main Methods:

• Engineered angiotensin-converting enzyme 2 (ACE2) for specific affinity capture of intact SARS-CoV-2.
• Utilized a microfluidic device with a staggered herringbone pattern and nanoparticle surface coating.
• Optimized processing conditions for enhanced sensitivity and detection.

Main Results:

• Achieved detection of as few as 3 viral copies per milliliter.
• Validated the assay on patient samples: 72% of plasma, 36% of saliva, and 29% of stool samples showed SARS-CoV-2 detection.
• Demonstrated longitudinal monitoring capability for tracking active viral infections over time.

Conclusions:

• The developed microfluidic device offers a highly sensitive method for detecting intact SARS-CoV-2 in complex biofluids.
• This technology has potential for widespread application in viral load monitoring and disease management.
• The platform is adaptable for detecting other viruses by utilizing relevant cell entry molecules.