Ultra-Stable 2D Magneto-Fluorescent Probe-Mediated Multiplex Immunochromatographic Assay for Precise Bedside Detection of Sepsis

Accurate bedside diagnosis of sepsis is essential for timely treatment and reducing mortality, yet technical limitations persist. Here, we present a multiplex-compatible lateral flow immunoassay (LFIA) that integrates a universal click-chemistry conjugation strategy with highly dispersible, film-like magnetic fluorescent probes (GFDQD@Si) to enable precise diagnosis through concurrent monitoring of pathogens and protein biomarkers. GFDQD@Si combines a two-dimensional high-area reactive interface; a magnetic interlayer for target enrichment and signal amplification; a multilayer of quantum dots for fluorescence enhancement; and an outer silica shell that suppresses background fluorescence and confers superior flowability. This architecture overcomes the size disparity between bacteria and proteins, enabling efficient cocapture of multiple proteins/bacteria and achieving faster, more sensitive detection on an LFIA platform. The platform quantitatively detects two key sepsis biomarkers─procalcitonin (PCT) and interleukin-6 (IL6)─as well as the pathogen Pseudomonas aeruginosa, with limits of detection of 4.44 pg mL –1 for PCT, 0.94 pg mL –1 for IL6, and 7 CFU mL –1 for bacteria. Validation in 75 clinical whole-blood samples demonstrated high sensitivity, ease of operation, and robustness, underscoring its potential for real-time bedside sepsis diagnosis. By simultaneously providing dual readouts of host-response biomarkers and pathogen detection, the GFDQD@Si-LFIA platform is expected to accelerate and improve clinical decision-making for sepsis.