Ruthenium(II)–terpyridine complexes-containing glyconanoparticles for one- and two-photon excited fluorescence imaging

Abstract

The synthesis of ruthenium(II)–terpyridine complexes-containing glyconanoparticles (Ru–GNPs) for one- and two-photon excited fluorescence imaging was described. Ru–GNPs were built from diblock copolymers of pentafluorophenyl acrylate (PFA) and 2-(2′,3′,4′,6′-tetra-O-acetyl-β-D-glucosyloxy)ethyl methacryalte (AcGlcEMA), prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. The pendant reactive pentafluorophenyl ester groups were substituted and the copolymer cross-linked by the two-photon absorption (TPA) chromophore, bis[4′-(4-aminophenyl)-2,2′:6′,2″-terpyridyl]ruthenium(II) hexafluorophosphate. After deacetylation of the acetyl-protecting groups in the AcGlcEMA block, TPA nanoparticles with cross-linked ruthenium(II)–terpyridine complexes as the core and glycopolymers as the corona were obtained. The resulting Ru–GNPs exhibit good water dispersity, one-photon absorption and emission and low cytotoxicity towards KB cell line. Ru–GNPs also undergo two-photon excitation when excited in the near-infrared (NIR, 720–880nm) in water, with TPA cross-sections in the range of 0.2–22 Göppert–Mayer (GM, 1 GM=10−50cm4s1photon−1). Ru–GNPs are thus potentially useful as effective cellular labeling agents for one- and two-photon excited fluorescence imaging.