Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan.
Bioelectrochemistry. 2010 Nov;80(1):26-30. doi: 10.1016/j.bioelechem.2010.04.004. Epub 2010 May 11.
We report a new technique for fabricating a single DNA nanowire at a desired position in a sequential manner using the micronanobubble generated by laser local heating at the Au/water interface. In our previous report, we found the reversible pull-in/shrinkage of one end immobilized DNA strands near a Nd:YAG laser focal point on an Au surface. In further experiments, the pinning of DNA strands in the stretched state was observed on the Au surface only when the bubble has touched the free end of DNA. This pinning phenomenon was observed even on the alkane thiol modified Au surface as self-assembled monolayers (SAMs) such as hexanethiol, mercaptohexanol, and hexadecanethiol. However, no pinning was observed on the bovine serum albumin (BSA) modified surface. Since optical tweezers can manipulate a DNA modified bead (radius=1.87 μm), the bead was firstly fixed on a solid surface by being compressed with the optical tweezers, and the pulling and pinning of DNA on the bead were achieved. As a consequence, the laser local heating on the Au surface enables us to control the number and position of the one end immobilized DNA strands as DNA nanowires.
我们报告了一种新的技术，使用激光局部加热在 Au/水界面产生的微纳米气泡，以顺序方式在所需位置制造单 DNA 纳米线。在我们之前的报告中，我们发现了在 Au 表面上 Nd:YAG 激光焦点附近固定的 DNA 链的一端的可逆拉入/收缩。在进一步的实验中，只有当气泡接触到 DNA 的自由端时，才观察到伸展状态下的 DNA 链在 Au 表面上的固定。这种固定现象甚至在烷硫醇修饰的 Au 表面（如己硫醇、巯基己醇和十六烷硫醇）作为自组装单层（SAM）时也观察到。然而，在牛血清白蛋白（BSA）修饰的表面上没有观察到固定。由于光镊可以操纵修饰有 DNA 的珠（半径=1.87 μm），首先通过光镊将珠压缩固定在固体表面上，从而实现对珠上 DNA 的拉伸和固定。因此，Au 表面上的激光局部加热使我们能够控制一端固定的 DNA 链的数量和位置，形成 DNA 纳米线。
