Non invasive Analysis of Thin Turbid Layers Using Microscale Spatially Offset Raman Spectroscopy

Here, we demonstrate, for the first time, theextension of applicability of recently developed microscalespatially offset Raman spectroscopy (SORS), micro-SORS,from the area of cultural heritage to a wider range of analyticalproblems involving thin, tens of micrometers thick diffuselyscattering turbid layers. The method can be applied insituations where a high turbidity of layers prevents thedeployment of conventional confocal Raman microscopy withits depth resolving capability. The method was appliedsuccessfully to detect noninvasively the presence of thin, highlyturbid layers within polymers, wheat seeds, and paper. Aninvasive, cross sectional analysis confirmed the micro-SORSfindings. Micro-SORS represents a new Raman imagingmodality expanding the portfolio of noninvasive, chemically specific analytical tools.