Surface plasmon coupled chemiluminescence

M. H. Chowdhury, S. N. Malyn, K. Aslan, J. R. Lakowicz, and C. D. Geddes. Multicolor directional surface plasmon-coupled chemiluminescence Journal of Physical Chemistry B, 2006, 110, 22644-22651. 

The concept of surface plasmon coupled cheluminescence has recently been reported by Geddes and co-workers [18]. The observation of surface plasmon-coupled chemiluminescence (SPCC)[18], where the luminescence from chemically induced electronic excited states couples to sur ce plasmons in a thin continuous metal film has been demonstrated for numerous metals [18]. This technology results in highly directional and polarized emission of the chemiluminescence from the prism side of the thin film in the SPCC geometry, as compared to traditional chemiluminescence isotropic slow-glow. 

Figure 15.17 Experimental geometry used for surface plasmon coupled chemiluminescence (SPCC). Top - View fi-om the top. Bottom - side view. Reproduced from Journal of Physical Chemistry B 110 22644-22651,2006.

Figure 15.18 (Top Left) shows the surface plasmon-coupled chemiluminescence (SPCC) and the fiee-space emission from a blue chemiluminescent dye on a 20 nm aluminum ftiin-film layer. It can be seen that the free-space emission is of much higher magnitude than the SPCC signal. This is...

C. D. (2006). Multicolor directional surface plasmon-coupled chemiluminescence of Physical Chemistry B 110 22644-22651. 

Abstract Optical detection continues to dominate detection methods in microfluidics due to its noninvasive nature, easy coupling, rapid response, and high sensitivity. In this review, we summarize two aspects of recent developments in optical detection methods on microfluidic chips. The first aspect is free-space (off-chip) detection on the microchip, in which the conventional absorption, fluorescence, chemiluminescence, surface plasmon resonance, and surface enhanced Raman spectroscopies are involved. The second aspect is the optofluidic (inside-chip) detection. Various miniaturized optical components integrated on the microfluidic chip, such as waveguide, microlens, laser, and detectors are outlined. 

Based on our research laboratory s observations of MEF from metals other than silver, MEC from chromium, coppo, nickel and zinc was also studied. Figure 1. 12 shows the enhancement factors for green chemiluminescence from diese metals with various thicknesses. A typical enhancement factor of 2-3-fold is observed from all metal surfaces, vdiich implies that chemically excited states can couple to these plasmon resonant metal particles. It is interesting to note that the chemiluminescence emission is dependent on the amount of reactants in the solution and diminishes once one of the reactants is used up. To test viiether the remainder of the inactive chemiluminescent dye can be excited with an external light source and still emit luminescence, additional experiments were undertaken where the chemiluminescence solution was excited with a laso at 473 nm. Interestingly, the inactive chemiluminescence dye can be optically excited and still emit luminescence with enhancement factors similar to the chemically excited conditions being observed. A detailed investigation of MEC from different metals is currently underway and will be reported in due course. 

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