Toma Koji, Dostalek Jakub, Knoll Wolfgang
AIT-Austrian Institute of Technology GmbH, Health and Environment Department, Vienna, Austria.
Opt Express. 2011 Jun 6;19(12):11090-9. doi: 10.1364/OE.19.011090.
A biosensor scheme that employs long range surface plasmons (LRSPs) for the efficient excitation and collection of fluorescence light from fluorophore-labeled biomolecules captured in a three-dimensional hydrogel matrix is discussed. This new approach to plasmon-enhanced fluorescence (PEF) is experimentally and theoretically investigated by using the Kretschmann configuration of attenuated total reflection (ATR) method. A layer structure supporting LRSPs that consists of a low refractive index fluoropolymer layer, a thin gold film and a large binding capacity N-isopropylacrylamide (NIPAAm)-based hydrogel matrix swollen in an aqueous sample is employed. By using this layer architecture, the extended field of LRSPs probes the binding of biomolecules in the binding matrix at up to micrometer distances from the gold surface. With respect to regular surface plasmon-enhanced fluorescence spectroscopy (SPFS) and surface plasmon-coupled emission (SPCE), a narrower angular distribution of the fluorescence light intensity, a larger peak intensity and the excitation and emission at lower angles were observed.
本文讨论了一种生物传感器方案，该方案利用长程表面等离子体激元（LRSPs）有效地激发和收集在三维水凝胶基质中捕获的荧光团标记生物分子发出的荧光。通过使用衰减全反射（ATR）方法的Kretschmann配置，对这种等离子体增强荧光（PEF）的新方法进行了实验和理论研究。采用了一种支持LRSPs的层结构，该结构由低折射率含氟聚合物层、薄金膜和在水性样品中溶胀的具有大结合容量的基于N-异丙基丙烯酰胺（NIPAAm）的水凝胶基质组成。通过使用这种层结构，LRSPs的扩展场可探测到距金表面高达微米距离的结合基质中生物分子的结合情况。与常规表面等离子体增强荧光光谱（SPFS）和表面等离子体耦合发射（SPCE）相比，观察到荧光光强度的角分布更窄、峰值强度更大以及在较低角度处的激发和发射。
