All the specific aims of this grant target the need to validate manufacturing strategies to fabricate nanowires with dimensions of 1-10 nm. Their fabrication is important since the advancement of modern technologies is directly related to our ability to manufacture devices composed of single molecular components. Current methodologies have low yields and rely on slow and serial protocols that are only applicable to research laboratories. In this grant we plan to utilize a long biomolecule, DNA, as a scaffold for the fabrication of magnetic nanowires. Such wires will be placed on optoelectronically important surfaces and used for the construction of nanoscale gaps on the order of a few nanometers. The gaps will be manufactured using endonucleases which are enzymes capable of cutting the DNA in a site-specific fashion despite the presence of magnetic materials on the surface. The gaps will b be useful for real device applications because the fabrication process will be compatible with standard semiconductor technology. This methodology is a massively parallel, can yield wires and gaps with variable sizes, it is low cost since one utilizes no equipment and only small amounts of biological materials are needed.
These studies will contribute to the understanding of how to address some of the major challenges in nanomanufacturing. More specifically the research strategy to fabricate nanoscale components via bio-inspired approaches fulfils the need to make and assemble nano-elements into devices and systems. Furthermore, the methodology we propose to validate offers a new route to meet challenges tied to precision control over placement and registration. The work has two main themes: i) understanding how to manufacture nanoscale gaps on electronically important surfaces using biomolecules called restriction enzymes; and ii) validation of an analytical framework to test the properties of the generated nanoscale gaps. A variety of fields ranging from (bio)sensors to electronic devices can benefit from the potential products of the nanomanufacturing processes we propose to develop. Undergraduate students who work on this project will also be involved in a community project, the Nanomanufacturing Demos, designed to introduce concepts of nanomanucturing to middle and high school students. Graduate students who participate in this research will be involved in a Nanomanufacturing Expo every year to help them learn to communicate to a broader audience the outcomes of their work. Overall, the work the students will do outside the laboratory can be exceptionally helpful to the education of the general public with respect to the impacts of nanoscience and engineering research and development.
We used DNA as a scaffold for the fabrication of magnetic and metallic nanowires for possible use in nanoscale devices. In regards to validate manufacturing strategies that fabricate gaps on surfaces with dimensions of 1-10nm, we introduced a potential methodology to localize and stretch DNA coated with magnetic nanoparticles between specific sets of electrodes. This study was an important accomplishment because we demonstrated that DNA-templated nanowires can be utilized in the construction of devices with small electrode gaps. Such gaps can be generated by cutting the DNA in specific locations using restriction enzymes. Furthermore, we accomplished studying the properties of nanoparticles scaffolded on DNA as magnetic nanowires. In another publication, we evaluated the magnetotransport properties of cobalt iron oxide NPs templated on DNA. We observed that the templating of magnetic nanoparticle on DNA produced a significant change in magnetoresistance and exhibited high sensitivity in current-voltage (IV) curves, which suggest that these nanowires exhibit potential use in magnetic device applications. The methodology we validated has enormous potential to allow the reliable production of nanoscale gaps in a massively parallel fashion. The protocol can also result in gaps with variable sizes. This is possible because the cutting location(s) along the wire are directly related to the programmable code of the DNA used as a template. The cost of the fabrication process is very low since one utilizes no equipment. In addition, only small amounts of biological materials are used to produce a number of gaps along numerous wires placed on large surface areas.
