A DNA-Based Method for Rationally Assembling Nanoparticles into Macroscopic Materials*
Chad A. Mirkin, Robert L. Letsinger, Robert C. Mucic, James J. Storhoff
Abstract
This chapter describes a method for assembling colloidal gold nanoparticles rationally and reversibly into macroscopic aggregates. The method involves attaching to the surfaces of two batches of 13-nm gold particles non-complementary DNA oligonucleotides capped with thiol groups, which bind to gold. One of the most successful approaches to date has involved the use of gold colloids and well established thiol adsorption chemistry. Oligonucleotide-based method allows the controlled and reversible assembly of gold nanoparticles into supramolecular structures. Oligonucleotides offer several advantages over non-biological-based linker molecules. An advantage of the DNA/colloid hybrid materials reported herein is that the assemblies can be characterized easily by transmission electron microscopy and/or atomic force microscopy as well as spectroscopic methods conventionally used with DNA. A beneficial consequence of capping the colloids with these oligonucleotides is that they are much more stable than bare gold colloids to increased salt concentration and temperature.