A Dual-Encoded Bead-Based Immunoassay with Tunable Detection Range for COVID-19 Serum Evaluation

Area of Science:

• Biomedical Engineering
• Immunology
• Infectious Diseases

Background:

• Serological assays are crucial for understanding coronavirus 2019 (COVID-19) progression, even in asymptomatic individuals.
• A need exists for sensitive, high-throughput detection methods capable of analyzing a wide range of analytes for effective COVID-19 management.

Purpose of the Study:

• To develop and validate a novel bead-based fluorescence immunoassay for simultaneous quantification of COVID-19 antibodies and inflammatory biomarkers.
• To achieve high sensitivity, multiplexing, and a broad detection range for comprehensive disease assessment.

Main Methods:

• Integration of color-size dual-encoded beads with rolling circle amplification (RCA) in a size-sorting chip.
• Quantification of antibodies against spike S1, nucleocapsid, and receptor binding domain antigens.
• Detection of inflammatory biomarkers including interleukin-6, interleukin-1β, procalcitonin, and C-reactive protein.

Main Results:

• The developed assay demonstrated high-throughput and sensitive detection of multiple COVID-19 related molecules.
• Tunable detection ranges were achieved by utilizing different bead sizes in conjunction with RCA.
• The assay successfully quantified antibodies and inflammatory biomarkers across concentration ranges from pg mL⁻¹ to μg mL⁻¹.

Conclusions:

• The integrated bead-based fluorescence immunoassay provides a versatile platform for sensitive, multiplexed serological analysis of COVID-19.
• This method can be readily adapted for simultaneous measurement of diverse COVID-19 serological markers, aiding disease progression and prognosis assessment.
• The assay's adaptability supports potential applications in diagnostics and therapeutic monitoring for infectious diseases.