Detectable compositions, methods of forming the same and detection techniques

摘要

In a technique for signal amplification in fluorescence detection or other analytical-detection techniques such as colourimetric or visual detection, a detectable unit (eg a fluorescent dye) is joined together with similar detectable units by means of a linker. The linker is designed to be cleaved in response to a preselected stimulus to release the individual detectable units. The linker may be selected from the group consisting of: phosphodiester linkages (eg as in figure 5); other enzyme-cleavable linkages; amide linkages; other photocleavable linkages; co-ordination complexes between a metal ion and a ligand; other acid-cleavable linkages; other base-cleavable linkages; ester linkages; ether linkages; silicon-based group linkages; acetal-based linkages; aminal-based linkages; orthoester-based linkages; orthoamide based linkages; and combinations of two or more of the above. The preselected stimulus may be selected from the group consisting of: treatment with a particular enzyme or class of enzymes; exposure to light, heat or other electromagnetic radiation; displacement by a stronger ligand; amide hydrolysis; treatment with an acid; treatment with a base; treatment with a particular chemical or chemical species; treatment with a particular ion or ionic species; hydrolysis; nucleophilic catalysis; or combinations of two or more of the above. The detectable units may be independently selected from the group consisting of: cyanine, xanthines, squarines, Rhodamines, phycobiliproteins, polymethines, phenoxazines thiazines, croconic acid (see figures 3 and 4). The invention further relates to methods of making detectable compositions and to detection techniques, especially immunoassays.