Abstract: A method of determining oxygen concentration, metabolic activity, and/or the effects of a test substance on the metabolic activity of a live cell sample by photoluminescence quenching technique employing a photoluminescent probe that self-loads sans any loading reagent into the cells of the cell sample. The probe comprises a plurality of polymeric particles each comprising an amphiphilic cationic polymer matrix having a hydrophobic core and a hydrophilic positively charged surface provided by quaternary amino groups, and a hydrophobic oxygen-sensitive photoluminescent dye embedded in the hydrophobic core.

Abstract: The invention is based on the use of photoluminescent probes for intracellular sensing of oxygen, especially assaying intracellular oxygen concentration. The photoluminescent probe comprises a suspension of polymeric particles having an average diameter in the 20 nm to 100 nm range, formed from an amphiphilic cationic co-polymer which is oriented in the formed particle to provide a hydrophobic core and a hydrophilic shell. The probe includes a hydrophobic oxygen-sensitive photoluminescent dye such as Pt-tetrakis(pentafluorophenyl)porphine, PtPFPP embedded in the hydrophobic core of the particle, and the co-polymer includes quaternary ammonium groups which provide hydrophilic and cationic character to the particle shell. The photoluminescent probe, which in use is provided in the form of an aqueous suspension of probe, is incubated with live mammalian cells in a suitable growth medium for a period of time to allow the probe particles passively load into the cells.

Abstract: A sensor material of the type comprising a long-decay photoluminescent, protonable dye embedded in a suitable polymeric matrix, is used for generating a specific optical response to two different analytes present in a sample, thus allowing selective determination of the two analytes in the sample. Also described is a method for the simultaneous sensing of a first and second analyte in a sample. The method comprises the steps of irradiating a sensor material of the type comprising a long-decay photoluminescent protonable dye embedded in a suitable polymeric matrix with light of one or two wavelengths, determining photoluminescence intensity and lifetime signals originating from the sensor, and correlating the photoluminescence intensity signal with a concentration of the first analyte and the photoluminescence lifetime signal(s) with the concentration of the second analyte.

Abstract: The invention is based on the use of photoluminescent probes for intracellular sensing of oxygen, especially assaying intracellular oxygen concentration. The photoluminescent probe comprises a suspension of polymeric particles having an average diameter in the 20 nm to 100 nm range, formed from an amphiphilic cationic co-polymer which is oriented in the formed particle to provide a hydrophobic core and a hydrophilic shell. The probe includes a hydrophobic oxygen-sensitive photoluminescent dye such as Pt-tetrakis(pentafluorophenyl)porphine, PtPFPP embedded in the hydrophobic core of the particle, and the co-polymer includes quaternary ammonium groups which provide hydrophilic and cationic character to the particle shell. The photoluminescent probe, which in use is provided in the form of an aqueous suspension of probe, is incubated with live mammalian cells in a suitable growth medium for a period of time to allow the probe particles passively load into the cells.

Abstract: A phosphorescent compound of general Formula I, or phosphorescent analogs thereof, wherein: at least one of R1 to R4 has a formula X—Y, wherein Y is a peptide sequence providing cell penetration, and X is absent or is a chemical linker; the or each of the remaining R1 to R4 groups are, independently, lipophilic, uncharged chemical groups; and Me is selected from Pt2+ or Pd2+, which probe is capable of measurement of molecular oxygen within live respiring cells by quenched-phosphorescence detection.

Abstract: A sensor material of the type comprising a long-decay photoluminescent, protonable dye embedded in a suitable polymeric matrix, is used for generating a specific optical response to two different analytes present in a sample, thus allowing selective determination of the two analytes in the sample. Also described is a method for the simultaneous sensing of a first and second analyte in a sample. The method comprises the steps of irradiating a sensor material of the type comprising a long-decay photoluminescent protonable dye embedded in a suitable polymeric matrix with light of one or two wavelengths, determining photoluminescence intensity and lifetime signals originating from the sensor, and correlating the photoluminescence intensity signal with a concentration of the first analyte and the photoluminescence lifetime signal(s) with the concentration of the second analyte.

Abstract: A method of assessing toxicity of a candidate agent to a sample of cells comprises the steps of providing a sample of cells, exposing the cells to the candidate agent for a suitable period of time, assaying the cells to measure data for at least one parameter of cellular function; and correlating the measured data of the at least one parameter of cellular function with toxicity, wherein the step of exposing the cells to the candidate agent is carried out in the presence of a reagent capable of facilitating transport of the candidate agent into the cell. The transport reagent may be an endocytosis, pinocytosis inducing agent, a peptide, or a liposome. The at least one parameter of cellular function may be selected from the group consisting of: cell viability; proliferation rate; membrane integrity; and a metabolic parameter.

Abstract: A probe for sensing and imaging intracellular oxygen comprises an oxygen-sensitive fluorescent or phosphorescent dye combined with a hydrophilic macromolecular carrier and a cell loading agent. A method for sensing cellular oxygen using the probe is also described.

Abstract: A probe comprises a supramolecular structure having a chemical or biological recognition moiety; a phosphorescent reporter label; and an effector which interacts with the label so that the probe alters its phosphorescent characteristics on recognition of a target. The phosphorescent reporter label may have an emission lifetime in the order of 1 ?s to 10 ms and may be selected from phosphorescent tetrapyrrolic compounds and their metallocomplexes.

Abstract: An assay device (1) comprises a base (2) and glass plate lid (3). The base (2) has an array of shallow microwells (4), each having a flat rim (9), all rims being co-planar. When the lid (3) is placed on the base (2) a thin capillary gap (10) is formed on each rim, acting as a liquid seal for a microwell chamber. The liquid is excess sample liquid and further excess is accommodated in overspill cavities (6) between the microwells (4). Because of the liquid seal and shallow configuration the benefits of microfluidic devices are achieved together with the handling convenience and use of conventional detection equipment of conventional microplate devices.

Abstract: An oxygen sensitive probe comprises a monofunctional derivative of an oxygen-sensitive photoluminescent dye covalently attached to a water soluble and/or hydrophilic macromolecular carrier. The probe may be a chemical conjugate of a monofunctional phosphorescent porphyrin dye and a poly(ethyleneglycol), polypeptide or polysaccharide.

Abstract: An assay device (1) comprises a base (2) and glass plate lid (3). The base (2) has an array of shallow microwells (4), each having a flat rim (9), all rims being co-planar. When the lid (3) is placed on the base (2) a thin capillary gap (10) is formed on each rim, acting as a liquid seal for a microwell chamber. The liquid is excess sample liquid and further excess is accommodated in overspill cavities (6) between the microwells (4). Because of the liquid seal and shallow configuration the benefits of microfluidic devices are achieved together with the handling convenience and use of conventional detection equipment of conventional microplate devices.