Patent ID: 7811809

Claim:
A molecular biosensor, the molecular biosensor comprising two epitope binding agent constructs, which together have formula (VI): R 47 —R 48 —R 49 —R 50 ; and R 51 —R 52 —R 53 —R 54 ; wherein: R 47 is an epitope-binding agent that binds to a first epitope on a target molecule and is selected from the group consisting of a peptide, a small molecule, and a protein; R 48 is a flexible linker attaching R 47 to R 49 ; R 49 and R 53 are a pair of complementary nucleotide sequences having a free energy for association from about 5.5 kcal/mole to about 8.0 kcal/mole at a temperature from about 21° C. to about 40° C. and at a salt concentration from about 1 mM to about 100 mM; R 50 and R 54 together comprise a detection means such that when R 49 and R 53 associate a detectable signal is produced; R 51 is an epitope binding agent selected from the group consisting of an antibody, an antibody fragment, peptide, protein, and an aptamer that binds to R 47 such that in the absence of a target molecule: (i) R 51 binds to R 47 , (ii) R 49 and R 53 associate, and (iii) R 50 and R 54 produce a detectable signal; and R 52 is a flexible linker attaching R 51 to R 53 .