Heinen L, Walther A
Institute for Macromolecular Chemistry , University of Freiburg , Stefan-Meier-Str. 31 , 79104 Freiburg , Germany . Email:
Freiburg Materials Research Center , University of Freiburg , Stefan-Meier-Str. 21 , 79104 Freiburg , Germany.
Chem Sci. 2017 May 1;8(5):4100-4107. doi: 10.1039/c7sc00646b. Epub 2017 Mar 31.
Functional DNA nanotechnology creates increasingly complex behaviors useful for sensing, actuation or computation, as enabled the integration of dynamic and responsive structural DNA motifs. However, temporally controlled and dynamic DNA structures with programmable lifetimes, that are able to operate autonomously and self-revert to the starting state are challenging to achieve due to tedious and very system-specific sequence design. Here, we present a straightforward concept to program transient lifetimes into DNA duplexes based on the pH-sensitive DNA i-motif switch. We integrate the i-motif switch with an internal, non-linear pH-resetting function using a rationally designed chemical reaction framework, by which the switch autonomously undergoes a complete "off-on-off"-cycle without the use of additional external triggers. The lifetime of the activated "on"-state ( the hybridized state) can be systematically programmed over several hours. The system can be readily implemented into hybrid DNA structures on larger length scales. Focusing on autonomous materials, we demonstrate temporal control of transient fluorescence signals and temporary aggregation of gold nanoparticles.
功能性DNA纳米技术创造出了越来越复杂的行为，这些行为在传感、驱动或计算方面很有用，这得益于动态和响应性结构DNA基序的整合。然而，由于繁琐且非常依赖特定系统的序列设计，要实现具有可编程寿命、能够自主运行并自我恢复到起始状态的时间可控动态DNA结构具有挑战性。在此，我们提出了一个简单的概念，即基于对pH敏感的DNA i-基序开关，将瞬态寿命编程到DNA双链体中。我们使用合理设计的化学反应框架，将i-基序开关与内部非线性pH重置功能相结合，通过该框架，开关无需额外的外部触发即可自主经历完整的“关-开-关”循环。激活的“开”状态（杂交状态）的寿命可以在数小时内进行系统编程。该系统可以很容易地应用于更大长度尺度的混合DNA结构中。以自主材料为重点，我们展示了对瞬态荧光信号的时间控制以及金纳米颗粒的临时聚集。
