Biomedical subjects

Andrew G Tennyson

Publications and source records attributed to Andrew G Tennyson.

4 recordsLinked to original sources

PubMed2006

Conjugated metallopolymers for fluorescent turn-on detection of nitric oxide.

A series of eight pi-conjugated polymers (CPs) composed of phenylenevinylene, phenyleneethynylene, fluorene, and thiophene derivatives have been prepared with bipyridyl or terpyridyl substituents within the pi-conjugated backbone or at side-chain positions. These ligand-modified CPs serve as macromolecular scaffolds for conducting metallopolymers. The optical and photoluminescent properties of the polymers and corresponding copper(II) metallopolymers were investigated. Copper(II) is a highly efficient quencher of CP emission (75-100% quenching). CPs featuring bipyridyl units within the CP backbone are quenched more efficiently than those with terpyridyl units. The copper(II) metallopolymer undergoes reduction to the corresponding copper(I) species upon reaction with nitric oxide, with concomitant changes in integrated emission ranging from a 50% decrease to a 320% increase. The positive emission response is largest when Cu(II) was bound to the CP through bipyridyl units within the backbone, making these materials the best candidates for NO sensing by a turn-on emission mechanism.

Copper↗

PubMed2006

Luminescent properties of water-soluble conjugated metallopolymers and their application to fluorescent nitric oxide detection.

Water-soluble pi-conjugated polymers (CPs) incorporating 5,5'-(2,2'-dipyridyl) (CP1) or 6,6'-(2,2'-dipyridyl) (CP2) units within the pi-conjugated backbone were prepared as scaffolds for macromolecular metal complexation. The response of CP emission to a range of metal ions was investigated in water, 10 mM aqueous sodium dodecyl sulfate, and acetonitrile/water (95:5). Cupric ions are the most efficient quenchers of CP emission, with K(SV) = 1.1 x 10(5) and 5.2 x 10(4) M(-1) in water for CP1a (40% bipyridyl monomer units) and CP1b (20% bipyridyl monomer units), respectively. Quenching is approximately twice as effective in acetonitrile/water (95:5) (K(SV) = 3.1 x 10(5) M(-1) for CP1a and 1.1 x 10(5) M(-1) for CP1b). Partial restoration of emission was observed upon exposure of Cu(II)-CP solutions to excess NO(g) in acetonitrile/water (95:5) or 10 mM SDS(aq).

2,2'-Dipyridyl↗

PubMed2006

Polymer-bound dirhodium tetracarboxylate films for fluorescent detection of nitric oxide.

A polymer-bound dirhodium complex, [{Rh2(O2CCH3)3(Ds-pip)}n(O2C-P)], was prepared via ligand exchange of [Rh2(O2CCH3)4] with the side chains of a methyl methacrylate/methacrylic acid copolymer (O2C-P) followed by axial coordination of the fluorophore, N-dansylpiperazine (Ds-pip). Emission from Ds-pip is quenched when coordinated to the dirhodium complex but can be restored upon displacement by analytes. Exposure of [{Rh2(O2CCH3)3(Ds-pip)}n(O2C-P)] films to aqueous nitric oxide (NO) evokes a 2.2-fold increase in integrated emission. The polymer matrix excludes potentially interfering analytes including reactive oxygen or nitrogen species, which cannot readily permeate the film.

Carboxylic Acids↗

PubMed2005

Conjugated polymer-based fluorescence turn-on sensor for nitric oxide.

A turn-on fluorescent sensor for NO (g) in solution was synthesized using a bipyridyl-substituted poly(p-phenylene vinylene) derivative (CP1) as the sensory scaffold. The action of NO (g) upon the CP1-Cu(II) complex reduces it to the CP1-Cu(I) complex with a concomitant 2.8-fold increase in emission intensity. The reagent is selective for NO (g) versus other biological reactive nitrogen species, except for nitroxyl, and has a detection sensitivity limit of 6.3 nM. [structure: see text]

Copper↗