Photoacoustic Spectroscopy and Related Techniques Applied to Biological Materials
The absorption of light by living organisms is important both as a probe of biochemical processes at the molecular level, and as the stimulus for myriad photobiological processes. Typically, light absorption may be characterized by measuring either the transmission or the reflectance spectrum; however, most biological systems in situ are not amenable to these measurements due to opacity, scattering, poorly defined or heterogeneous surface properties, etc. Thus, it is of interest to have a technique for measuring the absorption of light that is less constrained by the nature of the material under study. Photoacoustic spectroscopy (PAS) clearly meets this requirement while offering new information that arises uniquely from the combination of spectroscopic and calorimetric phenomena. In certain respects PAS is a qualitative spectroscopic technique, the spectra (except in special cases) are only similar to conventional absorption spectra; also for complex biological samples there is no general method of extracting extinction coefficients or concentrations from the observed signal. On the other hand, photophysical parameters such as quantum yields, lifetimes, and energies, characterizing the various excited states and relaxation pathways of photobiological systems in situ, can sometimes be measured by PAS.
KeywordsMirage Effect Photoacoustic Spectroscopy Purple Membrane Thermal Diffusion Length Photo Acoustic
Unable to display preview. Download preview PDF.
- Arata, H., and Parson, W. W., 1982, Enthalpy and volume changes accompanying electron transfer from P870 to the primary and secondary quinones in photosynthetic reaction centers, in: Function of Quinones in Energy Conserving Systems (B. L. Trumpower, ed.), Academic Press, New York (in press).Google Scholar
- Balasubramanian, D., and Rao, CH. M., 1981, Yearly Review, Photoacoustic spectroscopy of biological systems, Photochem. Photobiol. 34:749–752.Google Scholar
- Callis, J. B., 1976, The calorimetric detection of excited states, J. Res. Nat. Bur. Stand. 80A:413–419.Google Scholar
- Campbell, S. D., Yee, S. S., and Afromowitz, M. A., 1977, Two applications of photoacoustic spectroscopy to measurements in dermatology, J. Bioeng. 1:185–188.Google Scholar
- Garty, H., Cahen, D., and Caplan, S. R., 1978, Use of photoacoustic spectroscopy in the study of the bioenergetics of purple membranes, in: Energetics and Structure of Halophilic Microorganisms, (S. R. Caplan and M. Ginzburg, eds.), pp. 253–259, Elsevier/North-Holland Biomedical Press, Amsterdam.Google Scholar
- O’Hara, E. P., Tom, R., and Moore, T. A., 1981, Absorption of light by pigments in lichens studied by photoacoustic spectroscopy, Technical Digest, Second International Topical Meeting on Photoacoustic Spectroscopy, June 22–25, 1981, Optical Society of America, Washington, D.C. Abs. Tu B29.Google Scholar
- Ort, D. R., and Parson, W. W., 1978, Flash-induced volume changes of bacteriorhodopsin-containing membrane fragments and their relationship to proton movements and absorption transients, J. Biol. Chem. 253:6158–6164.Google Scholar
- Palmer, R. A., Roark, J. C., Robinson, J. C., and Howell, J. L., 1979, Photoacoustic detection of natural circular dichroism in solids, Technical Digest, Topical Meeting on Photoacoustic Spectroscopy, August 1–3, 1979, Optical Society of America, Washington, D.C. Abs. ThA 3–l.Google Scholar
- Pines, E., 1978, A new technique to assess sunscreen effectiveness, J. Soc. Cosmet. Chem. 29:559–564.Google Scholar
- Rosencwaig, A., 1978, Photoacoustic spectroscopy, Adv. Electr. Electron Phys. 46:207–311.Google Scholar
- Rosencwaig, A., and Pines, E., 1977a, A photoacoustic study of newborn rat stratum cor-neum, Biochim. Biophys. Acta 493:10–23.Google Scholar
- Yoon, G. J., Lee, T. Y., O’Hara, E. P., Moore, T. A., Yoon, M., and Song, P. S., 1981, The spectroscopy of Porphyra Sp. in situ, Can. J. Spectrosc. 26:148–157.Google Scholar