Short DNAzymes for Efficient Catalysis of “Click” Reactions in Solution and on Surface

We have systematically investigated and found surprising superior catalytic activities of very short DNAzymes for copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), both in solution and on surface. As a key reaction of the "click chemistry" class, CuAAC is a highly efficient and specific covalent conjugation tool with demonstrated applications in organic synthesis, bioconjugation, and surface functionalization; however, it requires the presence of the Cu(I) catalyst, which is an unstable species in aqueous solutions. We show here that one ultrashort, 14-nucleotide-truncated fragment of an earlier <i>in vitro</i> selected DNAzyme (CLICK-17) shows a striking and superior catalytic activity toward the <i>in trans</i> CuAAC reaction in solution and on surface in the presence of either Cu(I) or Cu(II), at significantly lowered concentrations. These results obviate the need for long-sequence DNAzymes, selected out of the homogeneous solution phase, for application in complex surface environments.