Tse Kiu-Yuen, Nichols Beth M, Yang Wensha, Butler James E, Russell John N, Hamers Robert J
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
J Phys Chem B. 2005 May 5;109(17):8523-32. doi: 10.1021/jp046433w.
Recent studies have shown that semiconductor surfaces such as silicon and diamond can be functionalized with organic monolayers, and that these monolayer films can be used to tether biomolecules such as DNA to the surfaces. Electrical measurements of these interfaces show a change in response to DNA hybridization and other biological binding processes, but the fundamental nature of the electrical signal transduction has remained unclear. We have explored the electrical impedance of polycrystalline and single-crystal diamond surfaces modified with an organic monolayer produced by photochemical reaction of diamond with 1-dodecene. Our results show that, by measuring the impedance as a function of frequency and potential, it is possible to dissect the complex interfacial structure into frequency ranges where the total impedance is controlled by the molecular monolayer, by the diamond space-charge region, and by the electrolyte. The results have implications for understanding the ability to use molecularly modified semiconductor surfaces for applications such as chemical and biological sensing.
最近的研究表明，诸如硅和金刚石之类的半导体表面可以用有机单分子层进行功能化，并且这些单分子层薄膜可用于将生物分子（如DNA）束缚到表面。对这些界面的电学测量表明，其响应会因DNA杂交和其他生物结合过程而发生变化，但电信号转导的基本性质仍不清楚。我们研究了通过金刚石与1-十二碳烯的光化学反应制备的有机单分子层修饰的多晶和单晶金刚石表面的电阻抗。我们的结果表明，通过测量电阻抗随频率和电位的变化，可以将复杂的界面结构分解为不同的频率范围，在这些频率范围内，总电阻抗分别由分子单分子层、金刚石空间电荷区和电解质控制。这些结果对于理解使用分子修饰的半导体表面进行化学和生物传感等应用的能力具有重要意义。
