These materials may play a role in the development of bio-nanoelectronic circuitry and 3D electronic power structures.

A five-and-a-half-year integrated multidisciplinary research project has been characterized by three themes pertinent to the development of advanced materials having tailorable microstructures and/or nanostructures. These themes are (1) biocompatible nanolithographic methods of patterning and templating of materials to have two- and three-dimensional nanostructures; (2) nucleic-acid-based approaches to preparing (both in solution and from predesigned, nanostructured surface templates) supramolecular structures tailored to perform specific functions; and (3) protein-based or inspired molecular and supramolecular architectures. The contributions of this and other related research projects can be expected to lead to the development of diverse nanostructured organic and inorganic materials and structures, including catalytic peptide tubes, hostguest materials for molecular separations, quantum-dot and magnetic-particle arrays, bio-nanoelectronic circuitry, photonicbandgap and three-dimensional electronic power structures, and novel biowarfare- detection materials.

From one perspective, the objectives of this research project have been the following:

• To establish the basic chemical and physical rules that govern the use of such biomolecules as those of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), peptide nucleic acid (PNA), peptides, and proteins for the assembly of two- and three-dimensional organic and inorganic structures having predictable and useful properties;
• To merge solution-phase strategies for assembly of three-dimensional nanostructures with surface-directed strategies that involve reliance on dip pen nanolithography (DPN); and
• To develop computational means of predicting the structural, optical, electrical, and mechanical properties of novel templated structures synthesized according to the abovementioned concepts.

A Nanofiber can be made by self-assembly of peptide amphiphile molecules that have been suspended in an acidic solution. Modification of the peptide sequence in the molecules changes the nature of fiber-surface molecular-recognition sites.

•Supramolecular Assembly Using Bio- Inspired Approaches
One group of researchers involved in this sub-project focused primarily on exploiting the structural features of selfassembling cyclic D, L-a-peptide nanotubes in the context of self-organizing organic conductors and semiconductors and secondarily on rational design of self-assembling peptide nanotubes carrying different structural and functional features suitable for the fabrication of new biologically active materials. Other groups involved in this sub-project addressed diverse topics, including collagen- like peptides and their threedimensional structures, polymer amphiphiles and formation of micelles, metal organic-based biomolecule nanoarrays, self-assembly of peptide amphiphile nanofibers (see figure), alignment of supramolecular structures based on peptide amphiphiles, a selfassembly system based on peptide lipid hybrid molecules, and synthesis of composite nanorods and assembly thereof into three-dimensional superstructures.