MnFe2O4 nanoclusters as labels for the quantitative detection of D‐dimer in a lateral‐flow immunochromatographic assay

In this study, MnFe₂O₄ nanoclusters were prepared as bioprobes to establish a lateral‐flow immunochromatographic assay (LFIA) for the rapid and quantitative detection of D‐dimer for the first time. The magnetic properties of the magnetic labels play a key role in the quantitative detection of biomolecules. The 47.3‐nm MnFe₂O₄ magnetic nanoclusters (MNCs) with good dispersion and high saturation magnetization (76 emu/g) were fabricated via thermal decomposition of Fe(acac)₃ with Mn(acac)₂. The prepared MnFe₂O₄ MNCs were well dispersed in water because the surfaces were fully covered with 3,4‐dihydroxyhydrocinnamic acid (DHCA) molecules by ligand exchange. Anti‐D‐dimer antibodies were coupled on the surface of MnFe₂O₄ MNCs, and the target protein, D‐dimer, was detected, in the range 0.05–6 μg/mL. This assay provides a promising platform for D‐dimer detection for point‐of‐care diagnosis.