Abstract
Rapid and precise serum cytokine quantification provides immense clinical significance in monitoring the immune status of patients in rapidly evolving infectious/inflammatory disorders, examplified by the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. However, real-time information on predictive cytokine biomarkers to guide targetable immune pathways in pathogenic inflammation is critically lacking, because of the insufficient detection range and detection limit in current label-free cytokine immunoassays. In this work, we report a highly sensitive localized surface plasmon resonance imaging (LSPRi) immunoassay for label-free Interleukin 6 (IL-6) detection utilizing rationally designed peptide aptamers as the capture interface. Benefiting from its characteristically smaller dimension and direct functionalization on the sensing surface via Au-S bonding, the peptide-aptamer-based LSPRi immunoassay achieved enhanced label-free serum IL-6 detection with a record-breaking limit of detection down to 4.6 pg/mL, and a wide dynamic range of ∼6 orders of magnitude (values from 4.6 to 1 × 10 6 pg/mL were observed). The immunoassay was validated in vitro for label-free analysis of SARS-CoV-2 induced inflammation, and further applied in rapid quantification of serum IL-6 profiles in COVID-19 patients. Our peptide aptamer LSPRi immunoassay demonstrates great potency in label-free cytokine detection with unprecedented sensing capability to provide accurate and timely interpretation of the inflammatory status and disease progression, and determination of prognosis.
Keywords: Antibody-derived peptide aptamer (ADPA); Interluekin-6 (IL-6); localized surface plasmon resonance (LSPR); nanoplasmonic immunoassay; severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
【저자키워드】 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)., nanoplasmonic immunoassay, localized surface plasmon resonance (LSPR), Interluekin-6 (IL-6), Antibody-derived peptide aptamer (ADPA), 【초록키워드】 SARS-CoV-2, Inflammation, coronavirus, pandemic, Biomarker, Prognosis, IL-6, peptide, cytokine, in vitro, immunoassays, Disease progression, immunoassay, serum, Patient, Interpretation, limit of detection, Rapid, information, quantification, COVID-19 patients, Immune status, Detection limit, Analysis, Predictive, interleukin 6 (IL-6, acute respiratory syndrome, disorders, profile, serum cytokine, inflammatory status, pathogenic inflammation, applied, provide, magnitude, immune pathway, 【제목키워드】 SARS-CoV-2, detection, aptamer, induced, enhanced,