Scheibel Thomas, Parthasarathy Raghuveer, Sawicki George, Lin Xiao-Min, Jaeger Heinrich, Lindquist Susan L
Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA.
Proc Natl Acad Sci U S A. 2003 Apr 15;100(8):4527-32. doi: 10.1073/pnas.0431081100. Epub 2003 Apr 2.
Recent research in the field of nanometer-scale electronics has focused on the operating principles of small-scale devices and schemes to realize useful circuits. In contrast to established "top-down" fabrication techniques, molecular self-assembly is emerging as a "bottom-up" approach for fabricating nanostructured materials. Biological macromolecules, especially proteins, provide many valuable properties, but poor physical stability and poor electrical characteristics have prevented their direct use in electrical circuits. Here we describe the use of self-assembling amyloid protein fibers to construct nanowire elements. Self-assembly of a prion determinant from Saccharomyces cerevisiae, the N-terminal and middle region (NM) of Sup35p, produced 10-nm-wide protein fibers that were stable under a wide variety of harsh physical conditions. Their lengths could be roughly controlled by assembly conditions in the range of 60 nm to several hundred micrometers. A genetically modified NM variant that presents reactive, surface-accessible cysteine residues was used to covalently link NM fibers to colloidal gold particles. These fibers were placed across gold electrodes, and additional metal was deposited by highly specific chemical enhancement of the colloidal gold by reductive deposition of metallic silver and gold from salts. The resulting silver and gold wires were approximately 100 nm wide. These biotemplated metal wires demonstrated the conductive properties of a solid metal wire, such as low resistance and ohmic behavior. With such materials it should be possible to harness the extraordinary diversity and specificity of protein functions to nanoscale electrical circuitry.
纳米级电子学领域的最新研究集中在小型器件的工作原理以及实现有用电路的方案上。与已有的“自上而下”制造技术不同，分子自组装正作为一种制造纳米结构材料的“自下而上”方法崭露头角。生物大分子，尤其是蛋白质，具有许多有价值的特性，但物理稳定性差和电学特性不佳阻碍了它们直接用于电路。在此，我们描述了利用自组装的淀粉样蛋白纤维构建纳米线元件的方法。酿酒酵母朊病毒决定簇Sup35p的N端和中间区域（NM）自组装产生了宽度为10纳米的蛋白质纤维，这些纤维在各种苛刻的物理条件下都很稳定。其长度可通过组装条件在60纳米至数百微米的范围内大致控制。一种经过基因改造的NM变体，带有可反应的、表面可及的半胱氨酸残基，被用于将NM纤维与胶体金颗粒共价连接。将这些纤维放置在金电极上，通过从盐中还原沉积金属银和金对胶体金进行高度特异性的化学增强，从而沉积额外的金属。所得的银线和金线宽度约为100纳米。这些生物模板化金属线展现出了固体金属线的导电特性，如低电阻和欧姆行为。利用这类材料，应该能够将蛋白质功能的非凡多样性和特异性应用于纳米级电路。
