Department of Physics and National Core Research Center for Nanomedical Technology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Biosens Bioelectron. 2010 Mar 15;25(7):1592-6. doi: 10.1016/j.bios.2009.11.017. Epub 2009 Nov 24.
We fabricated a capacitance sensor based on an anodized aluminum oxide (AAO) nanoporous structure to detect DNA hybridization. We utilized Au film deposited on the surface of the AAO membrane and Au nanowires infiltrating the nanopores as the top and bottom electrodes, respectively. When completely complementary target DNA molecules were added to the sensor-immobilized DNA molecule probes, the capacitance was reduced; with a concentration of 1pM, the capacitance decreased by approximately 10%. We measured the capacitance change for different concentrations of the target DNA solution. A linear relationship was found between the capacitance change and DNA concentration on a semi-logarithmic scale. We also investigated the possibility of detecting DNA molecules with a single-base mismatch to the probe DNA molecule. In contrast to complementary target DNA molecules, the addition of one-base mismatch DNA molecules caused no significant change in capacitance, demonstrating that DNA hybridization was detected with single nucleotide polymorphism sensitivity.
我们制作了一种基于阳极氧化铝 (AAO) 纳米多孔结构的电容传感器，用于检测 DNA 杂交。我们利用沉积在 AAO 膜表面的 Au 薄膜和渗透纳米孔的 Au 纳米线分别作为顶电极和底电极。当完全互补的靶 DNA 分子被添加到传感器固定的 DNA 分子探针中时，电容会降低；当浓度为 1pM 时，电容大约降低了 10%。我们测量了不同浓度的靶 DNA 溶液的电容变化。在半对数标度上，发现电容变化与 DNA 浓度之间存在线性关系。我们还研究了检测与探针 DNA 分子有单个碱基错配的 DNA 分子的可能性。与互补的靶 DNA 分子相比，添加一个碱基错配的 DNA 分子不会导致电容发生显著变化，表明可以检测到具有单核苷酸多态性敏感性的 DNA 杂交。
