The efficiency of surface-plasmon coupled emission for sensitive fluorescence detection.

Surface-plasmon coupled emission (SPCE) has emerged as a new and potentially powerful tool for highly sensitive fluorescence detection. In the case of SPCE, the fluorescence is collected through a semi-transparent thin metal film deposited on glass. We present a theoretical analysis of SPCE, studying the potential enhancement of the fluorescence collection efficiency, brightness, quantum-yield, and photostability. The results are compared with fluorescence detection on a pure glass surface. It is shown that SPCE does not lead to any improvement, but that the metal film actually reduces the sensitivity of fluorescence detection.