DNA-Templated Assembly of Multichromophore Aggregates and Nanoparticle Wires

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

The focus of this research involves the use of the minor groove of DNA as a template for the synthesis of helical assemblies. Helical aggregates of cyanines will be assembled, leading to right-handed helical morphology and materials with interesting optical properties. Neutral substituents on the dye will afford blue-shifted absorption spectra and quenched fluorescence within the aggregate while cationic substitution will yield aggregates with red-shifted absorption spectra and intense fluorescence. The aggregate structures will be characterized by optical and high-resolution NMR spectroscopies. Minor groove binding ligands will also be used to noncovalently link gold nanoparticles to DNA. By using repetitive DNA sequences, multiple nanoparticles will be assembled in a linear fashion along the DNA, effectively creating a 1-D array, or wire. Silver deposition can be used to form a continuous wire of silver metal along the DNA-gold template. With this award, the Organic and Macromolecular Chemistry Program is supporting the research of Dr. Bruce A. Armitage of the Department of Chemistry at Carnegie Mellon University. Dr. Armitage will focus his work on using DNA as a scaffold for the synthesis of helical assemblies of organic dyes and inorganic nanoparticles. The resultant materials could have nonlinear optical properties or afford conductive wires, respectively. The project also provides an excellent venue for the interdisciplinary training of undergraduate and graduate students and the project has been very successful at including underrepresented minority students.