Biochemical Synthesis and Manipulation of a 70 nm DNA Linker for the Assembly of DNA‐Functionalized Gold Nanoparticles

Abstract

AbstractDNA oligonucleotides are extraordinarily well suited as linkers for the programmable assembly of nanoparticles. To extend the scope of DNA‐directed particle assembly, a 70 nm DNA linker molecule for the DNA‐directed assembly of gold nanoparticles is synthesized by biochemical reactions. In particular, polymerase chain reaction (PCR) and subsequent restriction and ligation reactions are employed to synthesize the DNA linker, comprising a 178 base pair (bp) double helical core region supplemented with two sticky‐end binding sites of 12 nucleotides in length, attached to one of the core‐forming strands. The linker is used for the assembly of DNA‐functionalized gold nanoparticles employing yet another biochemical reaction, namely covalent linkage through the enzyme DNA ligase. The resulting nanoparticle assemblies are characterized by using atomic force microscopy. The methodology described here represents a general way of synthesizing programmable DNA linker molecules with dimensions that exceed those presently available by using chemical synthetic methods, and thus, supplements the synthetic toolbox of nanobiotechnology to asses complex and functional nanoparticle/linker architectures for potential applications in sensing and materials science.