Kinogea Inc., Berkeley, CA 94704, USA.
Nanotechnology. 2011 Jun 17;22(24):245710. doi: 10.1088/0957-4484/22/24/245710. Epub 2011 May 4.
Molecular probe arrays printed on solid surfaces such as DNA, peptide, and protein microarrays are widely used in chemical and biomedical applications especially genomic and proteomic studies (Pollack et al 1999 Nat. Genet. 23 41-6, Houseman et al 2002 Nat. Biotechnol. 20 270-4, Sauer et al 2005 Nat. Rev. Genet. 6 465-76) as well as surface imaging and spectroscopy (Mori et al 2008 Anal. Biochem. 375 223-31, Liu et al 2006 Nat. Nanotechnol. 1 47-52, Liu 2010 IEEE J. Sel. Top. Quantum Electron. 16 662-71). Unfortunately the printed molecular spots on solid surfaces often suffer low distribution uniformity due to the lingering 'coffee stain' (Deegan et al 1997 Nature 389 827-9) problem of molecular accumulations and blotches, especially around the edge of deposition spots caused by solvent evaporation and convection processes. Here we present, without any surface chemistry modification, a unique solid surface of high-aspect-ratio silver-coated silicon nanocone arrays that allows highly uniform molecular deposition and thus subsequent uniform optical imaging and spectroscopic molecular detection. Both fluorescent Rhodamine dye molecules and unlabeled oligopeptides are printed on the metallic nanocone photonic substrate surface as circular spot arrays. In comparison with the printed results on ordinary glass slides and silver-coated glass slides, not only high printing density but uniform molecular distribution in every deposited spot is achieved. The high-uniformity and repeatability of molecular depositions on the 'coffee stain'-free nanocone surface is confirmed by laser scanning fluorescence imaging and surface enhanced Raman imaging experiments. The physical mechanism for the uniform molecular deposition is attributed to the superhydrophobicity and localized pinned liquid-solid-air interface on the silver-coated silicon nanocone surface. The unique surface properties of the presented nanocone surface enabled high-density, high-uniformity probe spotting beneficial for genomic and proteomic microarrays and surface molecular imaging.
分子探针阵列印刷在固体表面上，如 DNA、肽和蛋白质微阵列，广泛应用于化学和生物医学应用，特别是基因组和蛋白质组学研究（Pollack 等人，1999 年，《自然遗传学》第 23 卷，第 41-6 页；Houseman 等人，2002 年，《自然生物技术》第 20 卷，第 270-4 页；Sauer 等人，2005 年，《自然评论遗传学》第 6 卷，第 465-76 页）以及表面成像和光谱学（Mori 等人，2008 年，《分析生物化学》第 375 卷，第 223-31 页；Liu 等人，2006 年，《自然纳米技术》第 1 卷，第 47-52 页；Liu 等人，2010 年，《IEEE 量子电子学汇刊》第 16 卷，第 662-71 页）。不幸的是，由于分子聚集和斑点的“咖啡渍”（Deegan 等人，1997 年，《自然》第 389 卷，第 827-9 页）问题，固体表面上印刷的分子斑点分布往往不均匀，尤其是在沉积斑点的边缘周围，这是由溶剂蒸发和对流过程引起的。在这里，我们提出了一种独特的具有高纵横比的银涂硅纳米锥阵列的固体表面，无需任何表面化学修饰，该表面允许高度均匀的分子沉积，从而实现后续均匀的光学成像和光谱分子检测。荧光罗丹明染料分子和未标记的寡肽都被印刷在金属纳米锥光子衬底表面上，形成圆形斑点阵列。与普通玻璃载玻片和银涂覆玻璃载玻片上的印刷结果相比，不仅实现了高印刷密度，而且还实现了每个沉积斑点中均匀的分子分布。通过激光扫描荧光成像和表面增强拉曼成像实验证实了无“咖啡渍”纳米锥表面上分子沉积的高均匀性和可重复性。分子均匀沉积的物理机制归因于银涂覆硅纳米锥表面的超疏水性和局部固定的固-液-气界面。所提出的纳米锥表面的独特表面特性实现了高密度、高均匀性的探针点，有利于基因组和蛋白质组学微阵列和表面分子成像。
