Improvement in fingerprinting capability of surface enhanced Raman spectrometry by simultaneous measurement of scattering signal and transmitted light

A method for simultaneous measurement of surface-enhanced Raman spectra (SERS) and absorbance changes occuring in colloid substrates is reported. The method provides information on the aggregation state of the colloid while the SERS spectrum is recorded. The relationship between colloid aggregation and SERS intensity is thus readily established, allowing recording of SERS spectra under the most favorable circumstances. Anomalous bands, which appear and disappear mainly at low concentration, are detected and studied