Chowdhury Mustafa H, Malyn Stuart N, Aslan Kadir, Lakowicz Joseph R, Geddes Chris D
Center for Fluorescence Spectroscopy, Medical Biotechnology Center, University of Maryland School of Medicine, Baltimore, Maryland, 21201, USA.
J Phys Chem B. 2006 Nov 16;110(45):22644-51. doi: 10.1021/jp064609j.
In reports over the past several years, we have demonstrated the efficient collection of optically excited fluorophore emission by its coupling to surface plasmons on thin metallic films, where the coupled luminescence was highly directional and polarized. This phenomenon is referred to as surface plasmon-coupled emission (SPCE). In this current study, we have extended this technique to include chemiluminescing species and subsequentially now report the observation of surface plasmon-coupled chemiluminescence (SPCC), where the luminescence from chemically induced electronic excited states couples to surface plasmons in thin continuous metal films. The SPCC is highly directional and predominantly p-polarized, strongly suggesting that the emission is from surface plasmons instead of the luminophores themselves. This indicates that surface plasmons can be directly excited from chemically induced electronic excited states and excludes the possibility that the plasmons are created by incident excitation light. This phenomenon has been observed for a variety of chemiluminescent species in the visible spectrum, ranging from blue to red, and also on a variety of metals, namely, aluminum, silver, and gold. Our findings suggest new chemiluminescence sensing strategies on the basis of localized, directional, and polarized chemiluminescence detection, especially given the wealth of assays that currently employ chemiluminescence-based detection.
在过去几年的报告中，我们已经证明通过将光学激发的荧光团发射与薄金属膜上的表面等离子体激元耦合，可以高效收集荧光，其中耦合发光具有高度的方向性和偏振性。这种现象被称为表面等离子体激元耦合发射（SPCE）。在当前的这项研究中，我们将该技术扩展到包括化学发光物质，随后报告了表面等离子体激元耦合化学发光（SPCC）的观测结果，即化学诱导电子激发态产生的发光与连续薄金属膜中的表面等离子体激元耦合。SPCC具有高度的方向性且主要为p偏振，这强烈表明发射来自表面等离子体激元而非发光体本身。这表明表面等离子体激元可以直接从化学诱导电子激发态激发，排除了等离子体激元由入射激发光产生的可能性。在可见光谱范围内，从蓝色到红色的多种化学发光物质以及在铝、银和金等多种金属上都观察到了这种现象。我们的发现基于局部、定向和偏振化学发光检测提出了新的化学发光传感策略，特别是考虑到目前采用基于化学发光检测的大量分析方法。
