DNAzyme-Catalyzed Click Chemistry for Facilitated Immobilization of Redox Functionalities on Self-Assembled Monolayers

• Published in: Journal of physical chemistry. C 2020-09, Vol.124 (35), p.19083-19090
• Main Authors: Gan, Ning, Liu, Kun, Qi, Lin, Zhang, Guojuan, Guo, Yujing, Sen, Dipankar, Yu, Hua-Zhong
• Format: Article
• Language: English
• Subjects: C: Surfaces, Interfaces, Porous Materials, and Catalysis
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.0c05150

Cu­(I)-catalyzed azide-alkyne cycloaddition (CuAAC), the representative reaction of modern “click chemistry”, has been broadly employed in organic synthesis, bio-labeling, and surface functionalization. Nevertheless, it has limitations such as posing a dilemma of either using high concentrations of Cu­(I) catalyst or suffering from slow kinetics. Herein, we demonstrate that a newly selected DNAzyme (CLICK-17; a 79-nucleotide, catalytic DNA single strand) can rapidly catalyze CuAAC to tether redox functionalities onto an electrode surface using low concentrations of either Cu­(I) or Cu (II). Particularly, the CLICK-17 DNAzyme, at μM concentrations, facilitated the covalent immobilization of ethynylferrocene (Fc-CCH) onto 1-azido-11-undecanethiolate self-assembled monolayers on gold (N3C11S-Au SAMs); as low as 50 μM Cu­(I) together with 4 μM DNAzyme was able to complete the coupling reaction within 30 min and the pseudo first-order reaction rate constant is 7 times higher than that using the Cu­(I) catalyst alone. It was also remarkable that the CLICK-17 DNAzyme is functional with Cu­(II) in the absence of an explicit reductant for the catalyzed surface immobilization of Fc-CCH on N3C11S-Au SAMs.