TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The device comprises a film of the composition, where the composition is a light emitting and/or carrier-transporting medium. In the device the composition comprises three association products, where each product is of a material and mucin, one of the materials is emitted in the red region of the electromagnetic spectrum, the second material is emitted in the green region of the electromagnetic spectrum and the third material is emitted in the blue region of the electromagnetic spectrum.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: Each of the first, second and further materials has an optical and/or electronic profile which is distinct from each of the other materials in the composition. The composition comprises: at least three materials, where each of the materials are chemically associated with a shielding agent; and three materials, where two of the materials each are chemically associated with a shielding agent, and each of the at least two materials is hydrophobic material, nanostructure or chromophore (preferred). The chromophore is: a polycyclic aromatic dye, fluorescent monomer, fluorescent polymer, metal complex dopant and dye, light emitting dopant or fluorescent dye (including phthalocyanine or porphyrin); or at least one of anthracene, tris(benzoylacetonato)mono(phenanthroline)europium(III) and tris-(8-hydroxyquinoline) aluminum. In the composition: the first association product is of anthracene and a shielding agent; the second association product is of tris(benzoylacetonato) mono(phenanthroline)europium(III) and a shielding agent; and the further association product is of tris-(8-hydroxyquinoline)aluminum and a shielding agent. The shielding agent is solubilizing agent capable of rendering each of the first, second and further materials water soluble. The solubilizing agent comprises a polypeptide backbone, bound to sugar units, which is a proteoglycan or glycoprotein including mucin (preferred) or transferrin. The composition is in the form of aqueous solution (preferred), non-aqueous solution, solid or a film. The solid film comprises: a material emitting in the red region of the electromagnetic spectrum; a material emitting in the green region of the electromagnetic spectrum; and a material emitting in the blue region of the electromagnetic spectrum, where each of the materials is chemically associated with mucin. EXAMPLE - No suitable example given.