Tokuhisa Hideo, Liu Jun'an, Omori Kazuhiro, Kanesato Masatoshi, Hiratani Kazuhisa, Baker Lane A
Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan.
Langmuir. 2009 Feb 3;25(3):1633-7. doi: 10.1021/la8033148.
In this paper we demonstrate control over the spacing of surface-modifying probe molecules through the use of labile dendron spacers. During this process, anchor molecules are first adsorbed to a surface, with dendron modifiers attached. Steric interactions of the bulky dendrons control the density of anchor molecules bound to the surface. The dendron branches are subsequently detached from the anchor molecules, and the anchors are chemically modified with probe molecules, resulting in a surface with controlled spacing between probe molecules. Control over this spacing is important when the probe size is small in comparison with the target molecule. This importance is demonstrated for the binding of protein (streptavidin) targets to the probe (biotin) surface. The effect of probe space control on the efficiency of target capture is evaluated by examining the binding of streptavidin to thiolated biotin for a series of mixed monolayers. Surface modification is monitored by Fourier transform infrared reflection absorption spectroscopy (FTIR-RAS). The relative concentration of probe molecules at the surface is measured using X-ray photoelectron spectroscopy (XPS) measurements. Thiolated-biotin surfaces with optimized spacing show an increased capture efficiency for streptavidin relative to surfaces with nonoptimal or no control over probe spacing, as measured by surface plasmon resonance (SPR) spectroscopy. These results are of potential significance for the optimization and fabrication of micro- and nanoarrays used in chemical and biochemical measurements.
在本文中，我们展示了通过使用不稳定的树枝状间隔物来控制表面修饰探针分子的间距。在此过程中，锚定分子首先吸附到表面，并连接树枝状修饰剂。庞大树枝状分子的空间相互作用控制着与表面结合的锚定分子的密度。随后，树枝状分支从锚定分子上脱离，锚定分子用探针分子进行化学修饰，从而得到一个探针分子间距可控的表面。当探针尺寸与目标分子相比较小时，控制这种间距很重要。这一点在蛋白质（链霉亲和素）靶标与探针（生物素）表面的结合中得到了证明。通过研究一系列混合单分子层中链霉亲和素与硫醇化生物素的结合，评估了探针空间控制对靶标捕获效率的影响。通过傅里叶变换红外反射吸收光谱（FTIR-RAS）监测表面修饰情况。使用X射线光电子能谱（XPS）测量来测定表面探针分子的相对浓度。通过表面等离子体共振（SPR）光谱测量，与探针间距未优化或无控制的表面相比，具有优化间距的硫醇化生物素表面对链霉亲和素的捕获效率有所提高。这些结果对于化学和生化测量中使用的微阵列和纳米阵列的优化和制造具有潜在意义。
