RNA complexes, method of their production and sensors and analytical methods involving same

A method of determining the presence of at least two analytes in solution through the formation of respective self-assembled RNA complexes, said method comprising the steps:

• (a) placing in contact with said solution the surface of two silicon cantilevers bound to respective monomeric units of an RNA molecule of a respective first and second type, each said monomeric unit comprising RNA having a first helical domain having a first and second binding site, said first helical domain connected to a second helical domain having a first and second binding site, and said monomeric unit of said first type comprising an aptamer adapted to react with the first of said two analytes, and said monomeric unit of said second type comprising an aptamer adapted to react with the second of said two analytes,
• wherein said solution contains additional monomeric units of an RNA molecule of a third and fourth type, each said monomeric unit comprising RNA having a first helical domain having a first and second binding site, said first helical domain connected to a second helical domain having a first and second binding site, such that monomeric units of said first, third and fourth types self-assemble by respective first binding sites interacting with first binding sites of respective adjacent monomeric units, and respective second binding sites interacting with second binding sites of respective adjacent monomeric units to form pairs of cognate interactions and so as to form said RNA complex in a circular closed complex on said respective silicon cantilever surface should said first analyte be present in said solution;
• and such that monomeric units of said second, third and fourth types self-assemble by respective first binding sites interacting with first binding sites of respective adjacent monomeric units, and respective second binding sites interacting with second binding sites of respective adjacent monomeric units to form pairs of cognate interactions and so as to form said RNA complex in a circular closed complex on said respective silicon cantilever surface should said second analyte be present in said solution;
• and
• (b) determining the presence or absence of said complexes on said respective silicon cantilever surfaces.