Luminescent Iridium(III)-Containing Block Copolymers: Self-Assembly into Biotin-Labeled Micelles for Biodetection Assays

Luminescent polymers containing Ir(ppy)(2)(bpy) PF6 complexes, biocompatible poly(ethylene glycol) (PEG) chains, and biotin moieties were synthesized via ring-opening metathesis polymerization. (ROMP). Their self-assembly in Water into micelles resulted in an increased quantum Yield compared to open polymer chains in acetonitrile, which is likely due to core rigidity and desolvation. Streptavidin coated-magnetic, beads were employed to analyze the binding ability: of these Micelles:The positioning of the molecular recognition moiety biotin within the polymer chain had a very significant. effect on the availability biotin an the, micelle surface and the ability of the micelles to bind to streptavidin. Simply attaching biotin to the end of the ROMP polymer yielded micelles in Which the biotin units were Shielded by the PEG Chains, whereas the synthesis of a new ROMP monomer containing biotin at the end Of the PEG chains resulted in improved surface availability of the biotin group. Preliminary experiments in which streptavidin was microcontact-printed onto functionalized glass coverslips also indicated specific binding between the micelles and streptavidin and further demonstrated the potential of these middle systems to function as luminescent probes in solid-phase biodetection assays.