Fig. 2. Characterization of aptamers. (a) Structural analysis of the aptamers was performed using NUPACK to predict the secondary structures. (b) Binding affinity determination for (A) Apt-5 (B) Apt-26 (C) Apt-28 (c) CD spectra of three aptamers. CD data is obtained with a 5 μM concentration in the presence of in 20 mM Na₃PO₄, pH 7.4, containing 100 mM KCl.