Plasmonically Enhanced Ultrasensitive Epitope-Specific Serologic Assay for COVID-19

Area of Science:

• Immunology
• Biotechnology
• Infectious Diseases

Background:

• Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) caused the COVID-19 pandemic.
• Current serology assays lack specificity for neutralization antibodies, offering limited insights into infection stage and immune protection.
• Need for sensitive, multiplexed detection of specific antibodies for accurate diagnosis and outcome prediction.

Purpose of the Study:

• To develop a rapid, ultrasensitive, and multiplexed method for quantifying epitope-specific antibodies against SARS-CoV-2.
• To overcome limitations of existing serological assays by detecting specific antibody responses.

Main Methods:

• Utilized an ultrabright fluorescent nanolabel (plasmonic-fluor) for enhanced immunoassay.
• Developed a plasmon-enhanced, multiplexed immunoassay for epitope-specific antibody detection.
• Assay completion time of 20 minutes with a 100-fold lower limit of detection compared to colorimetric methods.

Main Results:

• Demonstrated a rapid (20 min) and ultrasensitive quantification of epitope-specific antibodies, including isotypes and subclasses.
• Achieved a 100-fold lower limit of detection compared to traditional enzymatic assays.
• Revealed significant patient-to-patient variability in immune responses using convalescent plasma.

Conclusions:

• The developed plasmonically enhanced multiplexed serological assay is cost-effective, rapid, and ultrasensitive.
• This assay can precisely detect epitope-specific antibodies, offering benefits for epidemiology and clinical outcome prediction.
• Potential to improve understanding of immune protection against SARS-CoV-2 following infection or vaccination.