Westcott Nathan P, Yousaf Muhammad N
Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
Langmuir. 2008 Mar 18;24(6):2261-5. doi: 10.1021/la703744v. Epub 2008 Feb 16.
We show a straightforward, flexible synergistic approach that combines microfluidics, electrochemistry, and a general immobilization strategy to activate regions of a substrate selectively for the precise immobilization of ligands and cells in patterns for a variety of cell-based assays and cell migration and cell adhesion studies. We develop microfluidic microchips to control the delivery of electrolyte solution to select regions of an electroactive hydroquinone SAM. Once an electrical potential is applied to the substrate, only the hydroquinone exposed to electrolyte solution within the microfluidic channels oxidizes to the corresponding quinone. The quinone form can then react chemoselectively with oxyamine-tethered ligands to pattern the surface. Therefore, this microfluidic/electrochemistry strategy selectively activates the surface for ligand patterning that exactly matches the channel design of the microfluidic channel. We demonstrate the ease of this system by first quantitatively characterizing the electrochemical activation and immobilization of ligands on the surface. Second, we immobilize a fluorescent dye to show the fidelity of the methodology, and third, we show the immobilization of biospecific cell adhesive peptide ligands to pattern cells. This is the first report that combines microfluidics/electrochemistry and a general electroactive immobilization strategy to pattern ligands and cells. We believe that this strategy will be of broad utility for applications ranging from fundamental studies of cell behavior to patterning molecules on a variety of materials for molecular electronic devices.
我们展示了一种直接、灵活的协同方法，该方法结合了微流控技术、电化学和通用的固定策略，以选择性地激活底物区域，用于将配体和细胞精确固定成图案，以进行各种基于细胞的分析以及细胞迁移和细胞黏附研究。我们开发了微流控微芯片，以控制电解质溶液向电活性对苯二酚自组装单分子层（SAM）选定区域的输送。一旦向底物施加电势，只有微流控通道内暴露于电解质溶液的对苯二酚会氧化为相应的醌。然后醌形式可以与氧胺连接的配体进行化学选择性反应，从而对表面进行图案化。因此，这种微流控/电化学策略选择性地激活表面以进行配体图案化，该图案与微流控通道的通道设计完全匹配。我们通过首先定量表征表面上配体的电化学激活和固定来证明该系统的简便性。其次，我们固定一种荧光染料以展示该方法的准确性，第三，我们展示生物特异性细胞黏附肽配体的固定以对细胞进行图案化。这是第一份将微流控/电化学与通用的电活性固定策略相结合以对配体和细胞进行图案化的报告。我们相信，该策略将在从细胞行为的基础研究到为分子电子器件在各种材料上图案化分子等广泛的应用中具有实用价值。
