Gold nanoparticle wires made using RNA-based self-assembly.

Self-assembly or bottom-up techniques based on molecular recognition are attracting a great deal of interest for nanofabrication. One such technology is based on the use of self-assembling tecto-RNA that has been shown to be able to make structures with nanoscale features (<10 nm) over large areas of the order of several microns. The technique is extremely flexible in that different RNA designs can be used to create dramatically different patterns, and the technology has the potential to scale up so that it might be used to pattern whole chips, or even wafers. In a step towards using molecular recognition techniques to build devices such as electronic circuits or sensors it is necessary to be able to add device structures or link functional units together. The authors show that the tecto-RNA method can be extended to attach gold nanoparticles using DNA linkers. The self-assembling properties of the RNA can in turn be used to link together the gold nanoparticles to form wires and clusters in a Mg²⁺-ion controlled, as opposed to electrostatically aggregated, process. Using this method they have fabricated a gold nanoparticle wire between two nanoelectrodes and evaluated the electrical properties of the resultant device. [ABSTRACT FROM AUTHOR]