Self-Assembly of Enzymes on DNA Scaffolds: En Route to Biocatalytic Cascades and the Synthesis of Metallic Nanowires

• Published in: Nano letters Vol. 9; no. 5; pp. 2040 - 2043
• Main Authors: Wilner, Ofer I, Shimron, Simcha, Weizmann, Yossi, Wang, Zhen-Gang, Willner, Itamar
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13-05-2009
• Subjects: Benzothiazoles - chemistry; Catalysis; Chemical synthesis methods; Cross-disciplinary physics: materials science; rheology; DNA - biosynthesis; DNA - chemistry; DNA Replication; Enzymes - chemistry; Exact sciences and technology; Glucose - chemistry; Glucose Oxidase - chemistry; Gold - chemistry; Horseradish Peroxidase - chemistry; Hydrogen Peroxide - chemistry; Materials science; Metal Nanoparticles - chemistry; Methods of nanofabrication; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanowires - chemistry; Oxidation-Reduction; Physics; Quantum wires; Self-assembly; Sulfonic Acids - chemistry; Enzymes; Gold; Catalysts; Template reaction; Glucose; Hybridization; Amplification; Self-assembly; Sulfonic acids; Peroxidases; DNA; Growth mechanism; Oxidation; Nanowires; Nanostructured materials
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl900302z

DNA strands consisting of programmed sequence-specific domains were synthesized by the rolling circle amplification (RCA) process. The spatial positioning of glucose oxidase (GOx) and of horseradish peroxidase (HRP) on the RCA-synthesized DNA template via hybridization enabled the activation of the bienzyme cascade. The GOx-catalyzed oxidation of glucose yielded gluconic acid and H2O2, and the resulting H2O2 oxidized 2,2′-azino-bis[3-ethylbenzthiazoline-6-sulfonic-acid] (ABTS2−) in the presence of HRP. The enzyme cascade could not be activated in the absence of the organizing DNA template or in the presence of a foreign DNA. Also, Au NPs-functionalized GOx was hybridized with the RCA-synthesized single-stranded DNA. The biocatalytic growth of the NPs through the oxidation of glucose, in the presence of AuCl4 −, enabled the synthesis of 1−5 μm long Au wires, exhibiting a width of ca. 150 nm.