A portable high-sensitivity multiplex platform with magnetic bead-based proximity extension assay for sample-to-answer protein biomarker detection

Protein biomarker detection is essential for clinical decision-making, particularly in immune profiling, infectious disease monitoring, and decentralized diagnostic settings. Current point-of-care testing (POCT) platforms for protein biomarkers often encounter challenges related to high analytical sensitivity, multiplexing capability, and fully automated sample preparation. This study introduces MagPEA-POCT, a portable and fully integrated protein detection system that uniquely combines magnetofluidic manipulations for automated on-cartridge sample preparation with magnetic bead-based proximity extension assay (MagPEA). The platform provides a true sample-in, answer-out workflow, enabling simultaneous quantification of IL-6, IL-8, and IFN-γ directly from serum within 90 min, utilizing a compact automated analyzer and disposable microfluidic cartridge. Analytical validation demonstrated detection limits of 62.3 fg/mL for IL 6 along with 168.0 fg/mL for IL 8 and 231.9 fg/mL for IFN γ, representing a two order-of-magnitude improvement over standard ELISA methods. The modular design facilitates easy adaptation to diverse biomarker panels suitable for different disease applications. This scalable and field-deployable technology effectively integrates automated sample preparation with high-sensitivity multiplex analysis, significantly advancing accessible and reliable point-of-care diagnostics.