Significance This work introduces an ultrasensitive single protein capture and detection technique based on a bright fluorescent reporter probe that is sensed on a photonic chip with integrated microfluidics. We perform differentiated detection of single SARS-CoV-2 and influenza A antigens at clinically relevant concentrations from clinical nasal swab materials. This ultrasensitive capture and detection technique could one day be realized as a tool for molecular diagnostics at the point of care. The urgency for the development of a sensitive, specific, and rapid point-of-care diagnostic test has deepened during the ongoing COVID-19 pandemic. Here, we introduce an ultrasensitive chip-based antigen test with single protein biomarker sensitivity for the differentiated detection of both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A antigens in nasopharyngeal swab samples at diagnostically relevant concentrations. The single-antigen assay is enabled by synthesizing a brightly fluorescent reporter probe, which is incorporated into a bead-based solid-phase extraction assay centered on an antibody sandwich protocol for the capture of target antigens. After optimization of the probe release for detection using ultraviolet light, the full assay is validated with both SARS-CoV-2 and influenza A antigens from clinical nasopharyngeal swab samples (PCR-negative spiked with target antigens). Spectrally multiplexed detection of both targets is implemented by multispot excitation on a multimode interference waveguide platform, and detection at 30 ng/mL with single-antigen sensitivity is reported.
【저자키워드】 Integrated optics, biosensing, optofluidics, single antigen detection, 【초록키워드】 SARS-CoV-2, coronavirus, Biomarker, protocol, antibody, COVID-19 pandemic, point of care, diagnostic, diagnostics, Antigen, Protein, point-of-care, sensitivity, ultraviolet light, antigens, target, molecular, nasal swab, reporter, platform, Concentration, acute respiratory syndrome, urgency, fluorescent, PCR-negative, nasopharyngeal swab sample, probe, concentrations, reported, clinically, influenza A antigen, Significance, 【제목키워드】 SARS-CoV-2, multiplex, fluorescent, probe, influenza A antigen,