Nakano Katsuya, Kamei Ryoma, Kanao Eisuke, Hosomi Takuro, Yamada Sayaka Konishi, Ishihama Yasushi, Yanagida Takeshi, Kubo Takuya
Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Seinan Indusutries, Co. LTD, Kitagagaya 4-3-24, Suminoe-ku, Osaka 559-0011, Japan.
ACS Meas Sci Au. 2025 Feb 16;5(2):199-207. doi: 10.1021/acsmeasuresciau.4c00089. eCollection 2025 Apr 16.
Zinc oxide nanowires (ZnO nanowire, ZnO NWs) are nanostructures that have drawn attention as separation media for efficient biomolecules because of high biological compatibility and low cost. Development of the capillary column (ZnO column) using a ZnO NW to an inner wall has been reported, although there are only a few studies about molecular recognition of a ZnO NW regardless of numerous studies reporting ZnO NWs. In our previous studies, we conducted fundamental research to elucidate molecular recognition of ZnO NW and develop a novel liquid phase separation field. Consequently, we achieved baseline separation of mixed adenosine phosphate analytes using a phosphate buffer in the mobile phase. In this study, to improve the low resistance of ZnO NW toward a solvent, we covered a surface of ZnO NW with titanium oxide (TiO) thin layers using atomic layer deposition. As a result, the column (TiO NW column) showed high affinity toward acidic compounds like the ZnO column, strongly interacting with especially phosphate groups. Resistance of ZnO NW to a weak acidic buffer solution was then dramatically improved. This is because multipoint electrostatic interaction between the phosphate groups and the NW surface occurred. Next, we conducted capillary electrochromatography to examine the possibility for application of separation analysis. The elution order of the phosphorylated compound was successfully controlled by the migration solution containing aqueous acetonitrile with weak acids.
氧化锌纳米线（ZnO纳米线，ZnO NWs）是一种纳米结构，因其具有高生物相容性和低成本，作为高效生物分子的分离介质而备受关注。尽管关于ZnO纳米线的研究众多，但关于ZnO纳米线分子识别的研究却很少，不过已有报道将ZnO纳米线用于内壁的毛细管柱（ZnO柱）的开发。在我们之前的研究中，我们进行了基础研究，以阐明ZnO纳米线的分子识别并开发一种新型液相分离领域。因此，我们使用流动相中的磷酸盐缓冲液实现了混合磷酸腺苷分析物的基线分离。在本研究中，为了提高ZnO纳米线对溶剂的低耐受性，我们使用原子层沉积法在ZnO纳米线表面覆盖了氧化钛（TiO）薄层。结果，该柱（TiO NW柱）对酸性化合物表现出与ZnO柱一样的高亲和力，尤其与磷酸基团强烈相互作用。然后，ZnO纳米线对弱酸性缓冲溶液的耐受性得到了显著提高。这是因为磷酸基团与纳米线表面之间发生了多点静电相互作用。接下来，我们进行了毛细管电色谱法以研究分离分析应用的可能性。通过含有弱酸的乙腈水溶液的迁移溶液成功控制了磷酸化化合物的洗脱顺序。
