Dual-color ultrabright AIEgens nanoparticles-based lateral flow immunoassay for simultaneous quantitative detection of serum amyloid A protein and C-reactive protein.

Infectious diseases remain a significant global health challenge, necessitating rapid and accurate diagnostic tools to distinguish between bacterial and viral infections. Serum amyloid A (SAA) and C-reactive protein (CRP) are well-established biomarkers of infectious diseases, with CRP typically indicating bacterial infections. This study presents a novel dual-color ultrabright aggregation-induced emission luminogens (AIEgens) nanoparticle-based lateral flow immunoassay (DC-AIENPs-LFIA) for the simultaneous quantitative detection of SAA and CRP. We developed a dual-AIEgens-encapsulated nanoparticle with a large Stokes shift and a high quantum yield of 93% via fluorescence resonance energy transfer, thereby achieving high sensitivity and specificity. The DC-AIENPs-LFIA demonstrated excellent detection performance, with sensitivities of 1.77 μg/mL for SAA and 0.45 μg/mL for CRP, and showed strong correlations with chemiluminescence immunoassay results in clinical serum samples. The assay also exhibited robust discriminatory capacity in differentiating infected from non-infected individuals solely based on SAA and CRP concentrations. Meanwhile, the SAA/CRP ratio showed promise in differentiating bacterial from viral infections, with an area under the receiver operating characteristic curve of 0.95. This study highlights the potential of DC-AIENPs-LFIA as a rapid, sensitive, and reliable point-of-care test for infectious disease diagnosis. It also provides a reference for the development of biosensors capable of multiplex biomarker detection with synergistic diagnostic value.