This work presents recent developments in spatially offset and transmission Raman spectroscopy for noninvasive detection and depth prediction of a single SERS inclusion located deep inside ex vivo biological tissues. The concept exploits the differential attenuation of Raman bands brought about by their different absorption due to tissue constituents enabling to predict the inclusion depth. Four different calibration models are tested and evaluated to predict the depth of surface enhanced Raman scattering labelled nanoparticles, within an up to 40 mm slab of porcine tissue. An external measurement carried out in transmission mode, with a noninvasively built model on the analysed sample, is shown to be insensitive to variations of the overall thickness of the tissue yielding an average root-mean-square error of prediction of 6.7%. The results pave the way for future noninvasive deep Raman spectroscopy in vivo enabling to localise cancer biomarkers for an early diagnosis of multiple diseases.
Bibliographical noteFunding Information:
This work was supported by the Engineering and Physical Sciences Research Council grant EP/R020965/1.
© 2019 Science and Technology Facilities Council. Journal of Biophotonics published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Copyright 2020 Elsevier B.V., All rights reserved.