Patent ID: 7635571

Claim:
A method for determining the presence or concentration of an analyte in a medium, said method comprising: providing a reaction mixture comprising in combination: a medium suspected of containing an analyte; a first specific binding pair member bound to a water-insoluble solid support; a second specific binding pair member bound to a sensitizer, said sensitizer capable in its excited state of generating a reactive oxygen species, wherein the proximity of the first specific binding pair member with the second specific binding pair member is modulated by the presence of the analyte; and digoxigenin-linked biotin linked to the solid support through a reactive oxygen cleavable linker; incubating the reaction mixture; exciting the sensitizer, said excitation of the sensitizer causing the formation of reactive oxygen, which cleaves the cleavable linker and releases digoxigenin-linked biotin from the solid support; and detecting the released digoxigenin-linked biotin, the amount thereof being related to the amount of analyte in said medium.