Fiber-Optic Probes for in Vivo Raman Spectroscopy in the High-Wavenumber Region
- 20 September 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 77 (20) , 6747-6752
- https://doi.org/10.1021/ac0505730
Abstract
In vivo Raman spectroscopy, using fiber-optic probes is hindered by the intense background signal, which is generated in the fused-silica fibers, in the fingerprint region of the Raman spectrum (∼0−2000 cm-1). Optical filtering is necessary to obtain tissue spectra of sufficient quality. The complexity of fiber-optic probes for fingerprint Raman spectroscopy, in combination with size constraints and flexibility requirements for in vivo use have been a major obstacle in the development of in vivo diagnostic tools based on Raman spectroscopy. A setup for remote Raman spectroscopic tissue characterization in the high-wavenumber region (∼2400−3800 cm-1) is presented. It makes use of a single, unfiltered, optical fiber for guiding laser light to the sample and for collecting scattered light and guiding it back to a spectrometer. Such a simple configuration is possible because the fused-silica core and cladding of the fiber present almost no Raman background signal at these wavenumbers. Several commercially available optical fibers were tested with respect to Raman signal background, to determine their suitability for in vivo Raman spectroscopy measurements in the high-wavenumber region. Different fiber core, cladding, and coating materials were tested. Silica core−silica clad fibers, with an acrylate coating and a black nylon jacket, proved to be one of the best candidates. In vitro measurements on brain tissue of a 6-month-old pig were obtained with a remote high-wavenumber Raman setup. They illustrate the low background signal generated in the setup and the signal quality obtained with a collection time of 1 s.Keywords
This publication has 13 references indexed in Scilit:
- Tissue characterization using high wave number Raman spectroscopyJournal of Biomedical Optics, 2005
- Fiber optic probes for biomedical optical spectroscopyJournal of Biomedical Optics, 2003
- Determination of Water Concentration in Brain Tissue by Raman SpectroscopyAnalytical Chemistry, 2001
- In Vivo Confocal Raman Microspectroscopy of the Skin: Noninvasive Determination of Molecular Concentration ProfilesJournal of Investigative Dermatology, 2001
- In Vivo Detection of Dysplastic Tissue by Raman SpectroscopyAnalytical Chemistry, 2000
- Prospects forin vivoRaman spectroscopyPhysics in Medicine & Biology, 2000
- Raman Spectroscopic Methods for In Vitro and In Vivo Tissue CharacterizationPublished by Elsevier ,1999
- Raman Spectrometry with Fiber-Optic SamplingApplied Spectroscopy, 1996
- Raman spectroscopy for the detection of cancers and precancersJournal of Biomedical Optics, 1996
- A high-throughput Raman notch filter setReview of Scientific Instruments, 1990