Department of Nanoengineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
ACS Nano. 2010 Sep 28;4(9):5076-80. doi: 10.1021/nn101593d.
With the increasing demand in recent years for high-performance devices for both energy and health applications, there has been extensive research to direct the assembly of nanoparticles into meso- or macroscale single two- and three-dimensional crystals of arbitrary configuration or orientation. Inorganic nanoparticle arrays can have intriguing physical properties that differ from either individual nanoparticles or bulk materials. For most device applications, it is necessary to fabricate two-dimensional nanoparticle superlattices at programmed sites on a surface. However, it has remained a significant challenge to generate patterned arrays with long-range positional order because most highly ordered close-packed nanocrystal arrays are typically obtained by kinetically driven evaporation processes. In this report, we demonstrate a method to generate patterned nanocrystal superlattices by confining nanoparticles to geometrically defined 2-D DNA sites on a surface and using associative biomolecular interparticle interactions to produce thermodynamically stable arrays of hexagonally packed nanocrystals with significant long-range order observed over 1-2 μm. We also demonstrate the role of chemical and geometrical confinement on particle packing and obtaining long-range order. Finally, we also demonstrate that the formation of DNA-mediated nanocrystal superlattices requires both interparticle DNA hybridization and solvent-less thermal annealing.
近年来，人们对能源和健康应用的高性能器件的需求不断增加，因此广泛开展了将纳米粒子组装成介观或宏观尺度的任意形状和取向的二维或三维单晶的研究。无机纳米粒子阵列具有不同于单个纳米粒子或体材料的有趣物理性质。对于大多数器件应用，需要在表面上的预定位置制造二维纳米粒子超晶格。然而，由于大多数高度有序的密排纳米晶体阵列通常是通过动力学驱动的蒸发过程获得的，因此生成具有长程位置有序的图案化阵列仍然是一个重大挑战。在本报告中，我们展示了一种通过将纳米粒子限制在表面上的几何定义的 2-D DNA 位点，并利用关联的生物分子粒子间相互作用来产生具有显著长程有序的六方密排纳米晶体的热力学稳定阵列的方法，该方法可以生成图案化纳米晶体超晶格，观察到超过 1-2 μm 的长程有序。我们还证明了化学和几何限制在颗粒堆积和获得长程有序方面的作用。最后，我们还证明了 DNA 介导的纳米晶体超晶格的形成需要粒子间的 DNA 杂交和无溶剂热退火。
