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 mu g/mL. This assay provides a promising platform for D-dimer detection for point-of-care diagnosis.