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The syntheses of several norbornene block copolymers containing oligonucleotide and ferrocenyl side chains and their use in the electrochemical detection of DNA are described. Two kinds of DNA-containing block copolymers with either ferrocenyl or dibromoferrocenyl groups were prepared via ring-opening metathesis polymerization (ROMP). Based on these two distinct ferrocene derivatives, a triblock copolymer labeling strategy was developed. With this strategy, the identity of DNA target can be determined by the E1/2s of the ferrocenyl moieties and the ratio of peak currents. These polymers exhibit predictable and tailorable electrochemical properties, high DNA duplex stability, and unusually sharp melting transitions, which are highly desirable characteristics for DNA detection applications. Significantly, single-base mismatches could be easily detected using two distinct block copolymers as dual-channel detection probes in an electrochemical DNA detection format.

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A series of monodisperse amphiphilic diblock copolymers containing a high-density of covalently linked indomethacin as the hydrophobic block and pendant hexaethylene glycol monomethyl ether as the hydrophilic block have been synthesized from ring-opening metathesis polymerization (ROMP) using Cl 2(PCy3)2RudCHPh. Dynamic light scattering (DLS), transmission electron microscopy (TEM), and 1 H NMR spectroscopy have been used to investigate the directed-assembly of these polynorbornenebased copolymers into polymeric nanoparticles in aqueous media as a function of copolymer composition, concentration, and degree of polymerization. The block copolymers formed micelle-like aggregates in the aqueous phase with mean diameters ranging from 993 ( 270 nm to 94 ( 14 nm by TEM. In general, the aggregate size decreased as the overall copolymer length decreased. After incubation in an acidic environment (pH ) 3) at 37 °C for 48 h, 20% of the indomethacin was released from the nanoparticles.

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