Gryczynski Ignacy, Malicka Joanna, Gryczynski Zygmunt, Lakowicz Joseph R
Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201.
J Phys Chem B. 2004 Jul 27;108(33):12568-12574. doi: 10.1021/jp040221h.
In a recent report we demonstrated efficient collection of emission by coupling to surface plasmons on a thin silver film, resulting in a directional signal in the glass substrate. We call the phenomenon surface plasmon coupled emission (SPCE). In the present report we examined sulforhodamine 101 (S101) in thin polymer films on 50 nm thick gold films on glass. We observed efficient SPCE through thin gold films. This result was surprising because metallic gold is typically an efficient quencher of fluorescence. The energy effectively coupled through the gold film into the glass at a sharply defined angle, but somewhat less sharp than for a comparable silver film. About 50% of the total emission appeared as SPCE, irrespective of direct excitation or excitation via the plasmon resonance evanescent wave. The emission was p-polarized with different wavelengths appearing at different angles. The lifetime of S101 was mostly unaffected by the gold film. These results indicate that SPCE occurs over long distances, larger than for quenching by energy transfer to the gold. We conclude highly efficient detection devices can be constructed by using fluorophores on gold-coated surfaces.
在最近的一份报告中，我们展示了通过与薄银膜上的表面等离子体激元耦合来有效收集发射光，从而在玻璃基板中产生定向信号。我们将这种现象称为表面等离子体激元耦合发射（SPCE）。在本报告中，我们研究了玻璃上50纳米厚金膜上的聚合物薄膜中的磺基罗丹明101（S101）。我们观察到通过薄金膜产生了高效的SPCE。这一结果令人惊讶，因为金属金通常是一种有效的荧光猝灭剂。能量以一个清晰定义的角度有效地通过金膜耦合到玻璃中，但比类似银膜的情况稍不那么尖锐。无论直接激发还是通过等离子体激元共振倏逝波激发，约50%的总发射光表现为SPCE。发射光为p偏振，不同波长出现在不同角度。S101的寿命大多不受金膜影响。这些结果表明，SPCE发生的距离比通过能量转移到金上进行猝灭的距离更长。我们得出结论，通过在金涂层表面使用荧光团可以构建高效的检测装置。
