Patent ID: 7122383

Claim:
An assay for detecting the presence and or/amount of a target biological agent in a sample comprising: determining, in the absence of the sample, a fluorescence emitted by a composition comprising: (A) a fluorescer and (B) a receptor specific for both a target biological agent and a chemical moiety, wherein the fluorescer and the receptor are each affixed to a solid support; combining the composition with the sample and the chemical moiety; wherein the chemical moiety comprises a recognition element capable of binding to the receptor, a property-altering element, and a tethering element between the recognition element and the property-altering element, wherein in the presence of binding between the receptor and the target biological agent the fluorescence emitted by the fluorescer differs from that emitted in the absence of binding between the receptor and the target biological agent; determining the fluorescence emitted by the composition after combining the composition with the sample and the chemical moiety; wherein when the recognition element is bound to the receptor, the property-altering element is located sufficiently close to the fluorescer such that the fluorescence emitted by the fluorescer is altered from that emitted when binding between the receptor and the chemical moiety does not occur; and wherein the difference in fluorescence emitted after combining the composition with the sample and the chemical moiety compared to that emitted in the absence of the sample is indicative of the presence and/or amount of the biological agent.