By integrating cutting-edge nanomaterials with a user-friendly LFIA format, our mpLFIA technology represents a transformative advancement in POCT diagnostics. With its unparalleled sensitivity, portability, and adaptability to diverse biomarkers, this platform holds immense potential for early infectious disease detection, outbreak surveillance, and resource-limited settings where rapid, ultra-sensitive diagnostics are critical. Synthesis of Fe3O4@PDA seeds 250 μL of carboxylated Fe3O4 nanoparticles were diluted in 1.75 mL of Milli-Q water. The solution was centrifuged at 6,000 g for 10 minutes. After the supernatant was removed, the pellet was redispersed in 2 mL of Milli-Q water. 100 μL of CTAC was added to the sample, and the mixture was left to spin for 30 minutes. The nanoparticle solution was then centrifuged at 8,000 g for 5 minutes. After the removal of the supernatant, the pellet was redispersed in 1.5 mL DI water. 10 mg of dopamine hydrochloride was dissolved in 1 mL of Tris buffer to initiate polymerization. 500 μL of polydopamine (PDA) solution was added to the particles, and the mixture was left to spin overnight. After spinning, the particles were centrifuged three times at 6,000 g for 5 minutes. After the first two washes, the supernatant was removed, and the pellet was redispersed in 1.5 mL of DI water and 50 μL of CTAC. After the third wash, the supernatant was removed, and the pellet was redispersed in 2 mL of DI water.