SPECTROSCOPY
A wafer testing system at work
THE ROLE OF
stresses and strains. It is a widely used tool in the spectroscopy community for both quantitative and qualitative molecular analysis, with applications ranging from high-end university research to airport security screening. Because of the extensive range of applications for Raman spectroscopy, it can often be confusing to determine which spectrometer is best suited for any given application. To help alleviate this challenge this application note will provide an overview of three common applications: biomedical diagnostics; silicon wafer stress monitoring; and incoming material verifi cation, along with suggestions of a preferred spectrometer for each application.
R
aman spectroscopy uses inelastic scattering of photons off covalently bound molecules to identify functional groups, crystallinity and
Janel Kane explores Raman spectroscopy applications
RAMAN
MEDICAL DIAGNOSTICS Raman spectroscopy has been repeatedly shown to have massive potential for point-of-care medical diagnostics and monitoring due to its ability to provide a non-contact non-destructive molecular fi ngerprint of many common physiological biomarkers. In the fi eld of cancer detection alone there have been thousands of research papers published, ranging from applications such as interoperative cancer boundary detection during breast, brain and oral tumour removal to urine testing for monitoring lung cancer response to treatment. Not only are most common biomolecules, such as nucleic acids, proteins, lipids and fats highly Raman active due to their nonpolar molecular structure, but perhaps, more importantly, the abundance of water in these samples does not interfere with the spectra
due to the extreme polarity of water molecules. T is dichotomy between the scattering cross-sections of biological macromolecules and water is what allows Raman to be used on both tissue and bodily fl uids for the identifi cation of pathogens, blood disorders, cancers, and other abnormalities. Because of the complexity of biological molecules, they tend to produce much broader spectral features than most other Raman active molecules. While this lends itself to a reduction in overall signal effi ciency requiring longer integration times, it also means that the spectral range and resolution requirements of the device are often quite relaxed. T is is particularly evident in fi t-for-purpose instrumentation that is designed to only look at a select few spectra features. For this application a spectrometer such as the AvaSpec-Hero, is ideal due to its deep
www.scientistlive.com 37
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72
