ACS Appl Mater Interfaces. 2010 Aug;2(8):2171-4. doi: 10.1021/am100263t.
Two trifunctional (trimethoxy and triethoxy) and one difunctional (methyldimethoxy) 3-mercaptopropyl-alkoxysilanes were covalently tethered to thiolated DNA oligonucleotides in solution. After deposition as microarrays onto glass, the immobilized DNA probes were tested for hybridization ability by a florescence-based method. The results demonstrate a large enhancement in the fluorescence signal when the functionality of the silane tether is reduced from three to two. An XPS analyses revealed that this is not due to a higher DNA surface density. FTIR spectra of the spin-coated silanes showed that the trifunctional silanes form branched and cyclic siloxane moieties, whereas the difunctional silane generates predominantly short straight siloxane chains. Therefore, the propensity of trifunctional silanes to form more complex networks leads to conformations of the bound DNA which are less favorable for the specific interaction with the complementary strand. The data implicate that further significant improvements in the DNA hybridization ability are possible by adroit choice of the silane system.
三种三官能（三甲氧基和三乙氧基）和一种双官能（甲氧基二甲氧基）3-巯丙基烷氧基硅烷在溶液中与硫醇化 DNA 寡核苷酸共价连接。在沉积为微阵列到玻璃上后，通过基于荧光的方法测试固定化 DNA 探针的杂交能力。结果表明，当硅烷键的官能度从三减少到二时，荧光信号大大增强。XPS 分析表明，这不是由于 DNA 表面密度更高。旋涂硅烷的 FTIR 光谱表明，三官能硅烷形成支化和环状硅氧烷部分，而双官能硅烷主要生成短直硅氧烷链。因此，三官能硅烷形成更复杂网络的倾向导致与互补链特异性相互作用的结合 DNA 的构象不太有利。这些数据表明，通过巧妙选择硅烷体系，进一步显著提高 DNA 杂交能力是可能的。
