Short DNAzymes\nfor Efficient Catalysis of “Click”\nReactions in Solution and on Surface

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