Patent ID: 8431388

Claim:
A three-component molecular biosensor, the molecular biosensor comprising two epitope binding agent constructs and a signal construct, which together have the formula: R 36 —R 37 —R 38 ; R 39 —R 40 —R 41 ; R 44 —R 43 —R 42 —R 45 —R 46 wherein: R 36 is an epitope binding agent that binds to a first epitope on a target molecule; R 37 is a flexible linker attaching R 36 to R 38 ; R 38 and R 41 are a pair of nucleotide sequences that are not complementary to each other, but are complementary to two distinct regions in R 42 , such that when R 38 and R 41 bind to R 42 in the presence of said target molecule, a restriction endonuclease site recognized by a restriction endonuclease that cleaves double stranded DNA is created; R 39 is an epitope binding agent that binds to a second epitope on the target molecule; R 40 is a flexible linker attaching R 39 to R 41 ; R 42 is a single-stranded nucleotide sequence comprising a first region that is complementary to R 38 , and a second region that is complementary to R 41 , such that when R 38 and R 41 bind to R 42 in the presence of said target molecule, a restriction endonuclease site recognized by a restriction endonuclease that cleaves double stranded DNA is created; R 43 is a flexible linker attaching R 42 to R 44 ; R 44 is a first nucleotide sequence that is complementary to R 48 , and is attached to a first detection means; R 45 is a flexible linker attaching R 42 to R 46 ; and R 46 is a second nucleotide sequence that is complementary to R 44 , and is attached to a second detection means, such that in the absence of said target molecule R 44 and R 46 associate and a detectable signal is produced, and in the presence of said target molecule, R 36 and R 39 bind to the said target molecule and R 38 and R 41 bind to R 42 , creating a double stranded restriction endonuclease site that is cleaved by a restriction endonuclease that recognizes the double stranded restriction endonuclease site, wherein upon cleavage of R 42 , R 44 and R 46 dissociate, reducing the detectable signal.