Surface-Enhanced Resonance Raman Scattering of R-Phycoerythrin Adsorbed by Silver Hydrosols

Abstract

Surface-enhanced resonance Raman scattering (SERRS) of R-phycoerythrin adsorbed by silver hydrosols was obtained. There are thirty-five lines in its SERRS spectra. However, there is a “fluorescent packet” in its Raman spectra only. All lines are covered up by the “packet”. The SERRS spectra were enhanced and the fluorescence was quenched rapidly because of the formation of the hydrosol/phycoerythrobilin (PEB) complex and the interaction with the SERS-active surface of the metallic base. The R-phycoerythrin consists of PEB and its surrounding protein matrix, but the lines of PEB appeared in R-phycoerythrin SERRS spectra only. This result indicates again that a competitive binding exists in the binding of protein-bound chromophore (R-phycoerythrin) components with silver hydrosols; thus, the chromophores (PEB) are mainly responsible for the SERRS effect. Therefore, the SERRS technique is very useful for studying protein-bound chromophores.