Fabrication of multifunctional magnetic nanoparticles bearing metallocarbonyl probes and antibodies

Metallocarbonyl complexes and their bioconjugates display specific and intense absorption bands in the mid-IR spectral range assigned to the stretching vibrations of the carbonyl ligands which make them useful bioprobes to study biomolecular processes. Here we report the design, synthesis, and characterization of amine- and thiol-functionalized magnetic nanoparticles (MNP) and their conjugates with the metallocarbonyl complex (η5-cyclopentadienyl)Fe(CO)2(η1-N-maleimidato). The resulting metallocarbonyl-labeled magnetic nanoparticles were derivatized with rabbit IgG to provide IR reporter immunoprobes. The antigen binding capability of the bioconjugates was confirmed by ELISA.