CASTDan:Abstract25
Kostov, Y., Smith D.S.,Tolosa L., Rao G., Gryczynski, I., Gryczynski,Z., Malicka,J. ,Lakowicz J.R, (2005) Directional Surface Plasmon-Coupled Emission from a 3 nm Green Fluorescent Protein Monolayer, Biotechnol. Prog. . 21, 1731-1735
Abstract:
High-sensitivity detection schemes are of great interest for a number of applications.
Unfortunately, such schemes are usually high-cost. We demonstrate a low-cost
approach to a high-sensitivity detection scheme based on surface plasmon-coupled
emission (SPCE). The SPCE of a monomolecular layer of green fluorescent protein
(GFP) is reported here. The protein was electrostatically attached to a thin, SiO2-
protected silver film deposited on a quartz substrate. The visible, directional emission
of GFP was observed at a sharp, well-defined angle of 47.5° from the normal to the
coupling prism, and the spectrum corresponded to that of GFP. The SPCE resulting
from the reverse Kretschmann configuration showed a 12-fold enhancement over the
free space fluorescence. The directional emission was 97% p-polarized. The directionality
and high polarization can be coupled with the intrinsic spectral resolution of
SPCE to be used in the design miniaturized spectrofluorometers. The observation of
SPCE in the visible region of the spectrum from a monolayer of protein opens up new
possibilities in protein-based sensing.
