Arinaga Kenji, Rant Ulrich, Knezević Jelena, Pringsheim Erika, Tornow Marc, Fujita Shozo, Abstreiter Gerhard, Yokoyama Naoki
Fujitsu Laboratories Ltd., 10-1 Morinosato-Wakamiya, Atsugi 243-0197, Japan.
Biosens Bioelectron. 2007 Oct 31;23(3):326-31. doi: 10.1016/j.bios.2007.04.012. Epub 2007 Apr 29.
We report on a method to control the packing density of sulfur-bound oligonucleotide layers on metal electrodes by electrical means. In a first step, a dense nucleic acid layer is deposited by self-assembly from solution; in a second step, defined fractions of DNA molecules are released from the surface by applying a series of negative voltage cycles. Systematic investigations of the influence of the applied electrode potentials and oligonucleotide length allow us to identify a sharp desorption onset at -0.65 V versus Ag/AgCl, which is independent of the DNA length. Moreover, our results clearly show the pronounced influence of competitive adsorbents in solution on the desorption behavior, which can prevent the re-adsorption of released DNA molecules, thereby enhancing the desorption efficiency. The method is fully bio-compatible and can be employed to improve the functionality of DNA layers. This is demonstrated in hybridization experiments revealing almost perfect yields for electrically "diluted" DNA layers. The proposed control method is extremely beneficial to the field of DNA-based sensors.
我们报道了一种通过电学手段控制金属电极上硫键合寡核苷酸层堆积密度的方法。第一步，通过溶液自组装沉积致密的核酸层；第二步，通过施加一系列负电压循环从表面释放特定比例的DNA分子。对施加的电极电位和寡核苷酸长度影响的系统研究使我们确定相对于Ag/AgCl在-0.65 V时存在一个尖锐的解吸起始点，这与DNA长度无关。此外，我们的结果清楚地表明溶液中竞争性吸附剂对解吸行为有显著影响，其可防止释放的DNA分子重新吸附，从而提高解吸效率。该方法具有完全的生物相容性，可用于改善DNA层的功能。这在杂交实验中得到了证明，该实验表明电“稀释”的DNA层几乎具有完美的产率。所提出的控制方法对基于DNA的传感器领域极为有益。
