INTELLECTUAL MERIT: This project develops a method for constructing composite nanoscale wires and fibers using tobacco mosaic virus (TMV) as a template for assembly. TMV is a rod-like virus that has a tendency to undergo head-to-tail association under suitable conditions of pH and ionic strength. It is therefore attractive as a template for the formation of nanowires and/or nanofibers with a high aspect ratio and uniform diameter. In this work a number of monomeric materials will be caused to bind to the TMV template after which they will be polymerized into covalently linked wires and fibers. Proof of concept was demonstrated by binding and polymerizing the simple organic base aniline. Additional proposed monomers include ethylenedioxythiophene which can be expected to yield a polymer with considerably higher conductivity than polyaniline. Such structures could be useful in constructing nanoscale circuitry and other nanodevices. Conductive fibers (wires) are not the only species sought. Fiber-like inorganic structures can be prepared, for example, by coating TMV with tetraethoxysilane under mild acid conditions to produce long silica/TMV composite fibers. Because the organic and inorganic monomer units can be prepared with a variety of chemical and physical characteristics, one can hope to obtain TMV-templated fibers with desired electrical, optical, or magnetic properties. Binding of monomers to the template may be stabilized by electrostatic, hydrogen-bonded, or other forces, depending on the character of the monomer. The primary focus of the work will be to understand the fundamental factors that govern assembly of various monomer types along the TMV template. Significant attention will also be given to careful characterization of the polymerized nanostructures using microscopy, conductance, X-ray scattering, and nanomechanical measurements.
BROADER IMPACTS: An inexpensive, general method for preparing nanofibers and nanowires possessing desired mechanical, chemical, and physical characteristics can be expected to have broad applicability for the construction of various nanodevices. The proposal includes a plan for attracting high school and university students into scientific careers through a week-long Summer Workshop for Bionanoparticle Technology. It also provides a platform for interdisciplinary training of graduate and undergraduate research students.
" (08/01/07-07/31/12): Intellectual merits: Using rod-like viral particles as model starting materials, we have developed practical methods to prepare hybridized biomaterials which can be used in sensing, delivery and tissue engineering applications. Our major findings include: (1) developed a practical assembly process to synthesize virus-polymer hybridized fibers, (2) applied the resulted biocomposite fibers in sensing applications, (3) systematically investigated the conjugation chemistry of rod-like viral particles, (4) exploited the directed assembly of 1D nanoparticles in a confined space and the potential application in cell culturing and tissue engineering; and (5) used rigid polymer matrixes rpomoting the formation of superlattice structures. We have successfully achieved the specific objectives proposed in our original research plan, and have published 31 papers in peer-reviewed journals, 1 patent, and 5 book chapters. Our papers have been broadly reported and cited (4 of them were highlighted as cover story, 3 papers have been cited over 60 times so far). Broad Impacts: The interdiciplinary nature of the project has attracted many students from all disciplines to join our research team. Overall there were 8 graduate students (5 female) and 6 postdoctoral fellows involved in this project, and 46 undergraduate students working in the PI’s lab since starting date of this Award (31 are minority or female, 10 went to graduate schools). In addition, via this project, our group has established very productive collaborations with scientists in the DOE National Laboratories. This collaboration has greatly benefited the education and career development of our undergraduate and graduate students. Moreover, over 100 high school students have spent more than a week during the summer to attend the Adventure in Bionanotechnology Summer Program in the PI’s lab, which becomes a very popular summer program for high school students who are interested in science technology and engineering. Finally, the PI has committed to promote the involvement of under-representative students. One Fulbright scholar together with two other minority graduate students are working in his lab now. The PI is also collaborating with the local high schools to bring minority high school students working in bionano science related research projects. In 2012 and 2013, the PI also worked with the American Chemical Society and brought in minority students doing research in his research labs.
