Institute for Materials Research IMO, IMOMEC, Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium.
ACS Nano. 2012 Mar 27;6(3):2712-21. doi: 10.1021/nn300147e. Epub 2012 Mar 1.
In this article, we report on the heat-transfer resistance at interfaces as a novel, denaturation-based method to detect single-nucleotide polymorphisms in DNA. We observed that a molecular brush of double-stranded DNA grafted onto synthetic diamond surfaces does not notably affect the heat-transfer resistance at the solid-to-liquid interface. In contrast to this, molecular brushes of single-stranded DNA cause, surprisingly, a substantially higher heat-transfer resistance and behave like a thermally insulating layer. This effect can be utilized to identify ds-DNA melting temperatures via the switching from low- to high heat-transfer resistance. The melting temperatures identified with this method for different DNA duplexes (29 base pairs without and with built-in mutations) correlate nicely with data calculated by modeling. The method is fast, label-free (without the need for fluorescent or radioactive markers), allows for repetitive measurements, and can also be extended toward array formats. Reference measurements by confocal fluorescence microscopy and impedance spectroscopy confirm that the switching of heat-transfer resistance upon denaturation is indeed related to the thermal on-chip denaturation of DNA.
本文报道了一种基于变性的新型界面热阻方法，用于检测 DNA 中的单核苷酸多态性。我们观察到，接枝在合成金刚石表面上的双链 DNA 分子刷对固-液界面的热阻没有显著影响。与此相反，令人惊讶的是，单链 DNA 的分子刷导致了显著更高的热阻，并表现为热绝缘层。这种效应可用于通过从低到高热阻的切换来识别 ds-DNA 的熔点。通过这种方法确定的不同 DNA 双链体（无内置突变的 29 个碱基对和带有内置突变的 29 个碱基对）的熔点与通过建模计算得出的数据非常吻合。该方法快速、无标记（无需荧光或放射性标记物）、允许重复测量，并且还可以扩展到阵列格式。通过共焦荧光显微镜和阻抗谱的参考测量证实，变性时热阻的切换确实与 DNA 在芯片上的热变性有关。
