Aptamer sensor device

An aptazyme sensor device for detecting a ligand, said device comprising the following three components

• (a) an aptamer component, which comprises a binding site for a ligand,
• (b) a ribozyme component having a substrate binding site, wherein said ribozyme component has an enzymatic activity towards a substrate, which enzymatic activity can be switched on and off, and which, if switched on, results in generation of a detectable signal upon exposure of the ribozyme component to the substrate and upon binding of the substrate to the substrate binding site,
• (c) a communication component, which is a single or double stranded nucleic acid and links (a) to (b) and translates changes in the binding state of component (a) to component (b),
• wherein (a), (b) and (c) are covalently bound in the order of (a), (c), (b) and/or in the order of (b), (c), (a), or combinations thereof selected from (b), (c), (a), (c), (b), or (a), (c), (b), (c), (a),
• furthermore comprising
• (d) an inhibitory component, which comprises a single nucleotide strand covalently bound to a metal nanoparticle, wherein the single nucleotide strand specifically and selectively binds to the substrate binding site of component (b) such that the enzymatic activity in (b) is inhibited,
• wherein binding of the single nucleotide strand to the substrate binding site of component (b) is selectively interrupted after exciting plasmon resonance of the metal nanoparticle by irradiation of said metal nanoparticle with light,
• wherein the enzymatic activity of component (b) is switched on when
• (i) a ligand is bound to component (a) and
• (ii) the inhibitory component (d) is not bound to component (b).