Fig. 2. The comparison of Dz activity in the Apt/Dz catenane nanostructure (a) and the blocker DNA/Dz duplex (b) for TK1 mRNA detection at concentrations of 0, 100 pM, 1 nM, 5 nM, 10 nM, 15 nM and 20 nM. The TK1 mRNA was incubated with the Apt/Dz (100 nM) or the blocker DNA/Dz duplex (100 nM) for 2 h at 37 °C, followed by fluorescence measurements.