Influence of Ag colloid aggregation on porphyrin SERRS spectra monitored via Raman correlation spectroscopy

Correlation spectroscopy principle was applied to study Raman signal of the SERS active system consisting of Ag colloid and copper(II) 5,10,15,20-tetr akis (1-methyl-4-pyridyl) porphyrin. A multichannel Raman spectrometer was used to record sets of consecutive Raman spectra with sampling times of ten ths Dr units of seconds. SERRS spectra of two SERS-active formations assign ed to the porphyrin molecules on the surface of Ag particles and in the agg regates were isolated hy means of the statistical noise analysis. It has be en proved, that Raman correlation spectroscopy can be employed to resolve c omplete Raman spectra coming from either small or large objects levitating in liquid. (C) 2001 Elsevier Science B.V. All rights reserved.