DNAzyme switches for molecular computation and signal amplification.

We have created molecular switches that consist of nucleic-acid cleaving DNAzymes which are temporarily inactivated by hybridization with blocking oligonucleotides. The unique design of the switches offers significant advantages over existing methods. Firstly, the switches are activated by a nucleic acid-cleaving enzyme which can be made to function only in the presence of a specific target analyte. This allows for their use as reporter elements which can be easily adapted for use in computational logical operations. Secondly, the activation of each switch produces an active nucleic acid-cleaving DNAzyme as an output and this allows the switches to be modularly coupled to one another so that the output of one switch functions as the input of another. In addition, the switches are scalable, so that a single input target can produce more than one active DNAzyme output. These features therefore create the means for amplification of signal, which confers significant potential for future biosensing applications where detection of low quantities of target biomarkers is required.