DNA Grafting and Arrangement on Oxide Surfaces for Self-Assembly of Al and CuO Nanoparticles
DNA Grafting and Arrangement on Oxide Surfaces for Self-Assembly of Al and CuO Nanoparticles
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DOI：
10.1021/acs.langmuir.7b02159
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发表时间：
2017-10-31
期刊：
影响因子：
3.9
通讯作者：
Rossi, Carole
中科院分区：
文献类型：
--
作者：
Calais, Theo;Bourrier, David;Rossi, Carole
DNA 引导的纳米物体组装作为制造先进纳米材料结构的手段一直是许多研究的主题。然而，大多数应用都涉及贵金属，因为与其他材料一起使用存在根本性的困难。在这项工作中，我们提出了一种通用且系统的方法，用于用单链 DNA 寡核苷酸功能化和表征氧化物表面。该协议适用于铝和铜氧化物纳米颗粒，因为它们对制造高能异质纳米复合材料非常感兴趣。结合原子吸收光谱与传统的动态光散射和荧光测定法，可以精确定量链霉亲和素和生物素化 DNA 寡核苷酸的表面密度，并最大化其表面密度，为理解接枝机制提供基础。首先，两种纳米颗粒的链霉亲和素覆盖率始终低于总表面的 20%。其次，将 DNA 单链直接非特异性接枝到 Al 和 CuO 纳米粒子上很大程度上主导了整个功能化过程：类似于所有接枝 DNA 链的 95% 和 90% 分别化学吸附在 CuO 和 Al 纳米粒子表面上。杂交效率的测量表明，只有大约 5% 和大约 10% 的嫁接到 CuO 和 Al 表面的单链寡核苷酸参与杂交过程，这与链霉亲和素覆盖率精确对应，每个蛋白质占据 0.9 和 1.2 个寡核苷酸即可证明。在没有链霉亲和素涂层的情况下，化学吸附在 CuO 和 Al 上的单链寡核苷酸的杂交效率降低至仅约 2%，这证明了链霉亲和素的使用是合理的，尽管其表面占有率较差。最后，检查并讨论了直接化学吸附到氧化物表面上的 DNA 链的结构。
DNA-directed assembly of nano-objects as a means to manufacture advanced nanomaterial architectures has been the subject of many studies. However, most applications have dealt with noble metals as there are fundamental difficulties to work with other materials. In this work, we propose a generic and systematic approach for functionalizing and characterizing oxide surfaces with single-stranded DNA oligonucleotides. This protocol is applied to aluminum and copper oxide nanoparticles due to their great interest for the fabrication of highly energetic heterogeneous nanocomposites. The surface densities of streptavidin and biotinylated DNA oligonucleotides are precisely quantified combining atomic absorption spectroscopy with conventional dynamic light scattering and fluorometry and maximized to provide a basis for understanding the grafting mechanism. First, the streptavidin coverage is consistently below 20% of the total surface for both nanoparticles. Second, direct and unspecific grafting of DNA single strands onto Al and CuO nanoparticles largely dominates the overall functionalization process: similar to 95 and 90% of all grafted DNA strands are chemisorbed on the CuO and Al nanoparticle surfaces, respectively. Measurements of hybridization efficiency indicate that only similar to 5 and similar to 10% of single-stranded oligonucleotides grafted onto the CuO and Al surfaces are involved in the hybridization process, corresponding precisely to the streptavidin coverage, as evidenced by the occupancy of 0.9 and 1.2 oligonucleotides per protein. The hybridization efficiency of single-stranded oligonucleotides chemisorbed on CuO and Al without streptavidin coating decreases to only similar to 2% justifying the use of streptavidin despite its poor surface occupancy. Finally, the structure of directly chemisorbed DNA strands onto oxide surfaces is examined and discussed.