Subsurface Probing in Diffusely Scattering Media Using Spatially Offset Raman Spectroscopy
| Autor: | Ian P. Clark, Edward R. C. Draper, William F. Finney, Michael D. Morris, Anthony W. Parker, Pavel Matousek, Neil Everall, M. Towrie, Allen E. Goodship |
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| Rok vydání: | 2005 |
| Předmět: |
Materials science
Light Spectrum Analysis Raman Sensitivity and Specificity 01 natural sciences Spectral line law.invention 010309 optics symbols.namesake Optics Nephelometry and Turbidimetry law Stilbenes 0103 physical sciences medicine Polymethyl Methacrylate Scattering Radiation Tomography Optical Optical tomography Instrumentation Spectroscopy medicine.diagnostic_test business.industry Scattering Spatially offset Raman spectroscopy 010401 analytical chemistry Reproducibility of Results Laser Transmission Raman spectroscopy 0104 chemical sciences symbols Feasibility Studies Raman spectroscopy business Raman scattering |
| Zdroj: | ResearcherID CIÊNCIAVITAE |
| ISSN: | 1943-3530 0003-7028 |
| Popis: | We describe a simple methodology for the effective retrieval of Raman spectra of subsurface layers in diffusely scattering media. The technique is based on the collection of Raman scattered light from surface regions that are laterally offset away from the excitation laser spot on the sample. The Raman spectra obtained in this way exhibit a variation in relative spectral intensities of the surface and subsurface layers of the sample being investigated. The data set is processed using a multivariate data analysis to yield pure Raman spectra of the individual sample layers, providing a method for the effective elimination of surface Raman scatter. The methodology is applicable to the retrieval of pure Raman spectra from depths well in excess of those accessible with conventional confocal microscopy. In this first feasibility study we have differentiated between surface and subsurface Raman signals within a diffusely scattering sample composed of two layers: trans-stilbene powder beneath a 1 mm thick over-layer of PMMA (poly(methyl methacrylate)) powder. The improvement in contrast of the subsurface trans-stilbene layer without numerical processing was 19 times. The potential applications include biomedical subsurface probing of specific tissues through different overlying tissues such as assessment of bone quality through skin, providing an effective noninvasive means of screening for bone degeneration, other skeletal disease diagnosis, and dermatology studies, as well as materials and catalyst research. |
| Databáze: | OpenAIRE |
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