Department of Chemistry, University of Alberta, Edmonton, AB, Canada.
Biosens Bioelectron. 2013 Nov 15;49:133-8. doi: 10.1016/j.bios.2013.05.011. Epub 2013 May 14.
Dual pH and temperature sensitive microgel-based etalons were fabricated by sandwiching a "monolithic" microgel layer between two semitransparent, Au layers. The devices exhibit visual color and multipeak reflectance spectra, both of which primarily depend on the distance between the Au surfaces mediated by the microgel diameter. We found that a polycationic polyelectrolyte can penetrate through the Au overlayer to interact with negatively charged microgel confined between Au overlayers. In this submission we report that biotinylated polycationic polymer can penetrate through the Au overlayer of a poly (N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-AAc) microgel-based etalon and cause the microgel layer to collapse. The collapse results in a shift in the spectral peaks of the reflectance spectra. We found that the extent of peak shift depends on the amount of biotinylated polycation added to the etalon, which can subsequently be used to determine the concentration of streptavidin in solution at pM concentrations.
双层 pH 值和温度敏感微凝胶等离激元通过在两个半透明的 Au 层之间夹一层“整体”微凝胶层来制备。这些器件表现出可见的颜色和多峰反射光谱，这两者主要取决于由微凝胶直径介导的 Au 表面之间的距离。我们发现，带正电荷的聚电解质可以穿透 Au 覆盖层与带负电荷的微凝胶相互作用，后者被 Au 覆盖层限制。在本提交中，我们报告说，生物素化的聚阳离子聚合物可以穿透聚（N-异丙基丙烯酰胺）-共-丙烯酸（pNIPAm-co-AAc）微凝胶基等离激元的 Au 覆盖层，并导致微凝胶层坍塌。坍塌导致反射光谱的谱峰发生位移。我们发现，峰位移的程度取决于添加到等离激元中的生物素化聚阳离子的量，随后可以用来确定溶液中链霉亲和素在 pM 浓度下的浓度。
