Shyr Margaret H S, Wernette Daryl P, Wiltzius Pierre, Lu Yi, Braun Paul V
Beckman Institute, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, USA.
J Am Chem Soc. 2008 Jul 2;130(26):8234-40. doi: 10.1021/ja711026r. Epub 2008 Jun 10.
DNA-mediated interactions present a significant opportunity for controlling colloidal self-assembly. Using microcontact printing to achieve spatial control of DNA-surface patterning and DNA-functionalized polystyrene colloids, we report that DNA hybridization can be utilized for sequence-specific reversible self-assembly of well-ordered 2D colloidal arrays. Two essential indicators of DNA-hybridization mediated assembly were confirmed: thermal reversibility and sequence specificity. The arrays melted at 50 degrees C and reassembled when introduced to fresh colloid suspension, and sequence specificity with <1% nonspecific binding was confirmed using fluorescent polystyrene colloids. The real-time assembly of the colloids onto the periodically patterned substrate was monitored by simple laser diffraction to obtain assembly kinetics. Maximum surface coverage of DNA-mediated assembly was determined to be 0.593 for DNA-functionalized 100 nm polystyrene colloids, and 90% of the assembly was complete after 6.25 h of hybridization in 50 mM NaCl Tris buffer. We also demonstrate that DNAzymes, catalytic DNA molecules, can be incorporated into the design, and in the presence of 10 microM Pb(2+), the hybridization-induced array assembly can be disrupted via DNAzyme activity.
DNA介导的相互作用为控制胶体自组装提供了重大机遇。利用微接触印刷实现DNA-表面图案化和DNA功能化聚苯乙烯胶体的空间控制，我们报道DNA杂交可用于有序二维胶体阵列的序列特异性可逆自组装。确认了DNA杂交介导组装的两个重要指标：热可逆性和序列特异性。阵列在50摄氏度时熔化，并在引入新鲜胶体悬浮液时重新组装，使用荧光聚苯乙烯胶体确认了非特异性结合小于1%的序列特异性。通过简单的激光衍射监测胶体在周期性图案化底物上的实时组装，以获得组装动力学。对于DNA功能化的100纳米聚苯乙烯胶体，DNA介导组装的最大表面覆盖率确定为0.593，在50 mM NaCl Tris缓冲液中杂交6.25小时后，90%的组装完成。我们还证明，可以将DNA酶（催化性DNA分子）纳入设计中，并且在存在10 microM Pb(2+)的情况下，杂交诱导的阵列组装可通过DNA酶活性被破坏。
