Department of Chemistry, University of California, Berkeley , Berkeley, California 94720-1460, United States.
Materials Sciences Division, Lawrence Berkeley National Laboratories , Berkeley, California 94720-1460, United States.
J Am Chem Soc. 2017 Sep 13;139(36):12610-12616. doi: 10.1021/jacs.7b06385. Epub 2017 Aug 31.
DNA has unique capabilities for molecular recognition and self-assembly, which have fostered its widespread incorporation into devices that are useful in science and medicine. Many of these platforms rely on thiol groups to tether DNA to gold surfaces, but this method is hindered by a lack of control over monolayer density and by secondary interactions between the nucleotide bases and the metal. In this work, we report an electrochemically activated bioconjugation reaction as a mild, reagent-free strategy to attach oligonucleotides to gold surfaces. Aniline-modified DNA was coupled to catechol-coated electrodes that were oxidized to o-quinones using an applied potential. High levels of coupling could be achieved in minutes. By changing the reaction time and the underlying catechol content, the final DNA surface coverage could be specified. The advantages of this method were demonstrated through the electrochemical detection of the endocrine disruptor bisphenol A, as well as the capture of living nonadherent cells on electrode surfaces by DNA hybridization. This method not only improves the attachment of DNA to metal surfaces but also represents a new direction for the site-specific attachment of biomolecules to device platforms.
DNA 具有独特的分子识别和自组装能力，这促进了其广泛应用于科学和医学领域的各种器件。许多此类器件平台都依赖巯基将 DNA 连接到金表面，但这种方法存在单层密度控制不足和核苷酸碱基与金属之间的二级相互作用的问题。在这项工作中，我们报告了一种电化学激活的生物偶联反应，这是一种温和、无试剂的策略，可将寡核苷酸连接到金表面。使用施加的电势将苯胺修饰的 DNA 与邻苯二酚涂覆的电极偶联，从而将其氧化为邻苯醌。在数分钟内即可实现高水平的偶联。通过改变反应时间和底层邻苯二酚含量，可以指定最终的 DNA 表面覆盖率。该方法通过电化学检测内分泌干扰物双酚 A 以及通过 DNA 杂交在电极表面捕获活的非贴壁细胞，证明了其优势。该方法不仅提高了 DNA 与金属表面的结合能力，而且为生物分子在器件平台上的特异性附着提供了新的方向。
