Covalent Attachment of Gold Nanoparticles to DNA Templates
The ability to assemble nanoparticles into arrays, networks, and circuits in a precise and controlled manner is key to the fabrication of a variety of nanodevices. Networks of nanometer-sized metal or semiconductor islands, or quantum dots, may exhibit a variety of quantum phenomena, with applications in optical devices, nanometer-sized sensors, advanced computer architectures, ultra dense memories, and quantum-information science and technology. The challenge is that fabrication with nanoscale precision of nanoparticle arrays in a time and cost effective manner remains a formidable task. Interest in the concept of self-assembled nanostructures led to the idea of using DNA as a scaffold or template for the programmed assembly of nanoscale arrays. DNA can be modified with functional groups at predetermined sites to allow for the attachment of other molecules in a specific manner. We have designed and demonstrated a new approach for binding nanoparticles to DNA. Functionalized nanoparticles are covalently bound to internal, chemically modified bases on double-stranded DNA without the presence of destabilizing "nicks" along the DNA backbone. In addition, we report an approach for thiolating one end of the DNA/nanoparticle product and attaching it to a gold surface. The ability to attach one or both ends of the DNA/gold complex, after generation of the desired pattern, to fixed contacts or electrodes is necessary for nanodevices fabrication. Fig. 2 Fig. 2: Close-up of DNA bound to gold particles.