Solution-based single molecule imaging of surface-immobilized conjugated polymers.

The photophysical behavior of conjugated polymers used in modern optoelectronic devices is strongly influenced by their structural dynamics and conformational heterogeneity, both of which are dependent on solvent properties. Single molecule studies of these polymer systems embedded in a host matrix have proven to be very powerful to investigate the fundamental fluorescent properties. However, such studies lack the possibility of examining the relationship between conformational dynamics and photophysical response in solution, which is the phase from which films for devices are deposited.

Design and synthesis of monofunctionalized, water-soluble conjugated polymers for biosensing and imaging applications.

Water-soluble conjugated polymers with controlled molecular weight characteristics, absence of ionic groups, high emission quantum yields, and end groups capable of selective reactions of wide scope are desirable for improving their performance in various applications and, in particular, fluorescent biosensor schemes. The synthesis of such a structure is described herein. 2-Bromo-7-iodofluorene with octakis(ethylene glycol) monomethyl ether chains at the 9,9'-positions, i.

Synthesis of heteroleptic uranium (mu-eta(6):eta(6)-C6H6)2- sandwich complexes via facile displacement of (eta(5)-C5Me5)1- by ligands of lower hapticity and their conversion to heteroleptic bis(imido) compounds.

Reactivity studies on the sterically crowded [(C(5)Me(5))(2)U](2)(mu-eta(6):eta(6)-C(6)H(6)), 1, have revealed that eta(1)-ligands can displace one of the normally inert (eta(5)-C(5)Me(5))(1-) ligands in each metallocene unit to form a series of heteroleptic bimetallic sandwich complexes of nonplanar (C(6)H(6))(2-), namely, [(C(5)Me(5))(X)U](2)(mu-eta(6):eta(6)-C(6)H(6)), where X = N(SiMe(3))(2), OC(6)H(2)(CMe(3))(2)-2,6-Me-4, and CH(SiMe(3))(2). Displacement by an amidinate is also possible, that is, X = (i)PrNC(Me)N(i)Pr. This allows the multielectron reactivity of the (mu-eta(6):eta(6)-C(6)H(6))(2-) sandwich complexes to be studied as a function of ancillary ligands.

A modular monolayer coating enables cell targeting by luminescent yttria nanoparticles.

Luminescent Eu(3+)-doped Y(2)O(3) nanoparticles are functionalized for cell targeting using a modular, multisegmented approach based on a phosphonate monolayer platform. The first segment provides hydrolytic stability for the particle-organic interface; the second enables aqueous suspendability; the third is used to bond cell attachment molecules. In vitro imaging experiments showed enhanced cell attachment of activated nanoparticles conjugated with cell attachment peptides compared to control nanoparticles.

Surface modification of Y2O3 nanoparticles.

Rare earth ion-doped yttrium oxide (Y2O3) nanocrystals are nontoxic and can be prepared as upconversion materials for cellular imaging, but they do not suspend well in water. In contrast to their tendency to dissolve in acidic media, yttria (Y2O3) nanoparticles readily react with phosphonic acids to give phosphonate-bonded yttria particles. Through the choice of phosphonic acid, the hydrophilicity of the nanoparticles can be controlled.