文摘
Dimers of origami tiles are bridged by the Pb2+-dependent DNAzyme sequence and its substrate or by the histidine-dependent DNAzyme sequence and its substrate to yield the dimers T1–T2 and T3–T4, respectively. The dimers are cleaved to monomer tiles in the presence of Pb2+-ions or histidine as triggers. Similarly, trimers of origami tiles are constructed by bridging the tiles with the Pb2+-ion-dependent DNAzyme sequence and the histidine-dependent DNAzyme sequence and their substrates yielding the trimer T1–T5–T4. In the presence of Pb2+-ions and/or histidine as triggers, the programmed cleavage of trimer proceeds. Using Pb2+ or histidine as trigger cleaves the trimer to yield T5–T4 and T1 or the dimer T1–T5 and T4, respectively. In the presence of Pb2+-ions and histidine as triggers, the cleavage products are the monomer tiles T1, T5, and T4. The different cleavage products are identified by labeling the tiles with 0, 1, or 2 streptavidin labels and AFM imaging.