Patent ID: 7470516

Claim:
A method of detecting an analyte in a solution comprising: (a) providing a composition comprising an oligonucleotide and a fluorescent moiety attached to the oligonucleotide, wherein the oligonucleotide undergoes a conformational change upon contact with the analyte, and the fluorescent moiety undergoes a change of fluorescence upon the conformational change, and wherein the oligonucleotide comprises a first series of consecutive nucleotides comprising the sequence set forth in SEQ ID NO:1 and a second series of consecutive nucleotides comprising the sequence set forth in SEQ ID NO:2, wherein the first series of consecutive nucleotides is located at the 5′ end of the oligonucleotide and the second series of consecutive nucleotides is located at the 3′ end of the oligonucleotide, wherein a 3′ portion of the first series of consecutive nucleotides hybridizes with a 5′ portion of the second series of consecutive nucleotides, and wherein a 5′ portion of the first series of consecutive nucleotides hybridizes with a 3′ portion of the second series of consecutive nucleotides of SEQ ID NO:2, and wherein the oligonucleotide is 25 to 120 nucleotides in length; (b) quantitating the fluorescence of the fluorescent moiety of the composition in the absence of the analyte; (c) subsequently contacting the composition with the solution containing the analyte; (d) quantitating the fluorescence of the fluorescent moiety of the composition in contact with the solution containing the analyte; and (e) comparing the fluorescence quantitated in step (b) with that quantitated in step (d), wherein a change in the fluorescence quantitated in step (d) as compared with the fluorescence quantitated in step (b) indicates that the analyte is present in the solution.