Disclosed is a method of facilitating detection of a
nucleic acid target sequence. The method may include obtaining a toehold-mediated
DNA strand displacement apparatus comprising a portion complementary to the
nucleic acid target sequence. The method may further include obtaining an
RNA toehold switch comprising an
RNA sequence comprising an inverted loop with a sequestered
ribosome binding site and a sequestered translation
start codon, a
transducer sequence on the 3′ side of the inverted loop, coding for a reporter
protein, and a toehold portion on the 5′ side of the inverted loop. Further, the toehold portion of the
RNA sequence may be complementary to a portion of the Toehold-mediated
DNA strand displacement apparatus. The method may further include combining the Toehold-mediated
DNA strand displacement apparatus and the RNA toehold switch in an
assay, such that the two are never in direct physical contact with each other. Accordingly, a sample containing the
nucleic acid target sequence on the substrate may displace a
nucleic acid strand from the toehold-mediated
DNA strand displacement apparatus and bind a portion of it to the RNA toehold switch resulting in expression of the reporter
protein.