Mirkin C A, Letsinger R L, Mucic R C, Storhoff J J
Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Nature. 1996 Aug 15;382(6592):607-9. doi: 10.1038/382607a0.
Colloidal particles of metals and semiconductors have potentially useful optical, optoelectronic and material properties that derive from their small (nanoscopic) size. These properties might lead to applications including chemical sensors, spectroscopic enhancers, quantum dot and nanostructure fabrication, and microimaging methods. A great deal of control can now be exercised over the chemical composition, size and polydispersity of colloidal particles, and many methods have been developed for assembling them into useful aggregates and materials. Here we describe a method for assembling colloidal gold nanoparticles rationally and reversibly into macroscopic aggregates. The method involves attaching to the surfaces of two batches of 13-nm gold particles non-complementary DNA oligonucleotides capped with thiol groups, which bind to gold. When we add to the solution an oligonucleotide duplex with 'sticky ends' that are complementary to the two grafted sequences, the nanoparticles self-assemble into aggregates. This assembly process can be reversed by thermal denaturation. This strategy should now make it possible to tailor the optical, electronic and structural properties of the colloidal aggregates by using the specificity of DNA interactions to direct the interactions between particles of different size and composition.
金属和半导体的胶体颗粒因其微小（纳米级）尺寸而具有潜在有用的光学、光电和材料特性。这些特性可能会带来包括化学传感器、光谱增强剂、量子点和纳米结构制造以及显微成像方法等应用。现在可以对胶体颗粒的化学成分、尺寸和多分散性进行大量控制，并且已经开发出许多方法将它们组装成有用的聚集体和材料。在此，我们描述一种将胶体金纳米颗粒合理且可逆地组装成宏观聚集体的方法。该方法包括将带有与金结合的硫醇基团的非互补DNA寡核苷酸连接到两批13纳米金颗粒的表面。当我们向溶液中加入具有与两个嫁接序列互补的“粘性末端”的寡核苷酸双链体时，纳米颗粒会自组装成聚集体。这种组装过程可以通过热变性来逆转。现在，通过利用DNA相互作用的特异性来指导不同尺寸和组成的颗粒之间的相互作用，这种策略应该能够定制胶体聚集体的光学、电子和结构特性。
