School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2009 Nov;74(4):991-9. doi: 10.1016/j.saa.2009.09.010. Epub 2009 Sep 10.
We have constructed a novel molecular assembly attached to quartz, oxidized silicon and indium-doped tin oxide coated substrates, where a tethered pyrene derivative is co-immobilized with oligo-N-isopropyl acrylamide (oligo-NIPAM). The addition of tethered oligo-NIPAM to the adlayer creates two different, temperature-dependent microenvironments for the surface-bound pyrene. X-ray photoelectron spectroscopy (XPS) and ellipsometry measurements demonstrate the covalent attachment of both oligo-NIPAM and pyrene in our adlayers. Contact angle results confirm the thermo-responsive nature of the oligo-NIPAM on the substrate surface. Steady-state fluorescence data show that the presence of oligo-NIPAM moieties reduces the extent of pyrene excimer formation and provides different environments for the chromophore at temperatures above and below the phase transition. Fluorescence lifetime decay data on surface-bound pyrene are biexponential, consistent with multiple local environments, regardless of whether tethered oligo-NIPAM is present or not. Quenching studies reveal that we can manipulate the sensing properties of this new film simply by adjusting the conformations of oligo-NIPAM.
我们构建了一种新型的分子组装体，附着在石英、氧化硅和掺铟锡氧化物涂覆的基底上，其中一个连接的芘衍生物与寡聚 N-异丙基丙烯酰胺（寡聚 NIPAM）共同固定化。寡聚 NIPAM 加到吸附层中，为表面结合的芘创造了两种不同的、温度依赖的微环境。X 射线光电子能谱（XPS）和椭圆测量证明了我们吸附层中寡聚 NIPAM 和芘的共价附着。接触角结果证实了寡聚 NIPAM 在基底表面的热敏性质。稳态荧光数据表明，寡聚 NIPAM 部分的存在降低了芘激基复合物的形成程度，并在相变温度以上和以下为发色团提供了不同的环境。表面结合芘的荧光寿命衰减数据是双指数的，与多个局部环境一致，无论是否存在连接的寡聚 NIPAM。猝灭研究表明，我们可以通过简单地调整寡聚 NIPAM 的构象来操纵这种新型薄膜的传感特性。
