Patent ID: 8431051

Claim:
A polymeric nanoparticle suitable for a biological application, comprising a medium for photon up-conversion and a stabilizing agent, said medium comprising at least two components and a polymeric organic matrix component, said polymeric organic matrix component forming a polymeric matrix in which polymeric matrix said at least two components are distributed, wherein a first component of said at least two components is capable of absorbing light at a first wavelength region λ 1 , which first component acts as a sensitizer in said medium, and wherein a second component of said at least two components is capable of emitting light at a second wavelength region λ 2 , which second component acts as an emissive component in said medium, wherein λ 2 ≦λ 1 , and wherein, upon absorption of light by said first component at said first wavelength region λ 1 , said emissive component emits light at said second wavelength region λ 2 , wherein said first component and said second component are organic compounds, wherein said stabilizing agent is a polymer selected from the group consisting of hydrophilic polymers and amphiphilic polymers, said amphiphilic polymers having a hydrophobic part and a hydrophilic part, wherein said hydrophobic part also forms part of said polymeric matrix, wherein said amphiphilic polymer is selected from the group consisting of amphiphilic copolymers, hydrophobic polymers with a covalently attached hydrophilic part, hydrophilic polymers with a covalently attached hydrophobic part, and polyelectrolytes having a hydrophobic part, wherein the polymeric organic matrix comprises a hydrophobic polymer selected from the group consisting of polystyrenes, styrene-butadiene copolymers, polystyrene-based elastomers, polyethylenes, polypropylenes, polytetrafluoroethylenes, extended polymethylsiloxane, polyphenylmethylsiloxanes, modified polysiloxanes, polyethers, polyurethanes, polyether-urethanes, polyethylene terephthalates, and polysulphones, wherein the first component is an organic dye having a populated triplet or mixed triplet-singlet state, a two-photon absorbing dye, an optical limiting component, or a carbon nanotube, wherein the second component is an organic dye having fluorescence emission of from 360 to 750 nm, and wherein said biological application is labeling cells, detection of cells, biological (macro-) molecules or other analytes, fluorescence microscopy, (flow) cytometry, fluorescence-activated cell sorting (FACS), fluorescence resonance energy transfer (FRET), immunohistochemistry, clinical immunoassay, fluorescence-quenching-based enzyme-activity assay, high-throughput screening, molecular diagnostic, sensing of temperature, sensing of pressure, sensing of oxygen, sensing of other substances that influence the up-conversion process in cells and tissues, or singlet oxygen generation.