$100,000 Raman or $30,000 FT-Raman detector should be compelling indeed. Frontiers SERS can provide unique insight for diverse chemical problems. When used in combination with other techniques such as IR spectroscopy and micros copy, SERS can contribute enormously to our understanding of complex inter faces and interfacial processes. The sensitivity and rich spectral informa tion that SERS provides have spurred the rapid development of technology for using SERS as an analytical detec tion method. SERS is becoming ever more accessi ble to the analytical chemist. New sub strates such as "photocolloids" (30) and silver-coated membranes (15) are eliminating the tedium of colloid and electrode preparation. The availability of IR lasers used with Fourier trans form Raman spectrometers considera bly augments the range of substrate materials for which the surface-en hancement effect can be observed, ex tending the range of analytical prob lems for which SERS can provide use ful insight (4,31,32). The feasibility of performing FTSERS experiments with Nd:YAG la sers and roughened noble metal elec trode substrates has recently been demonstrated (31, 32). New low-cost Raman spectrometers (approximately $20,000) based on diode lasers as well as small monochromators, inexpensive multichannel detectors, and personal computers, will make conventional Ra man spectroscopy, SERS, and SERRS readily available to analytical and pro cess control chemists. Advances in la ser and detector technology will facili tate surface-enhanced hyper-Raman scattering (SEHRS) experiments that provide even richer spectroscopic in formation than SERS. New approach es to Raman spectroscopy such as Hadamard imaging will also have an im pact on SERS. Finally, theoretical and experimental studies of the enhance ment mechanisms will contribute to our understanding of the chemical and physical interactions between adsorbates and surfaces, providing the fun damental basis for designing chemical interfaces for analytical applications. The author thanks the National Science Founda tion, the PPG Foundation, BP America, and the Eastman Kodak Company for support of this work, and Angela Ahem and Tonya Heme for thoughtful suggestions. References (1) Fleischmann, M.; Hendra, P. J.; McQuillan, A. J. Chem. Phys. Lett. 1974, 26,163. (2) Moskovits, M. Rev. Mod. Phys. 1985, 57,783.
(3) Jiang, X.; Campion, A. Chem. Phys. Lett. 1987,140,95. (4) Zeman, E. J.; Schatz, G. C. J. Phys. Chem. 1987,97,634. (5) Weitz, D. Α.; Garoff, S.; Gramila, T. J. Opt. Lett. 1982, 7,168. (6) Moskovits, M.; DiLella, D. P.; Maynard, K. J. Langmuir 1988,4,67. (7) Golab, J. T.; Sprague, J. R.; Carron, K. T.; Schatz, G. C.; Van Duyne, R. P. J. Chem. Phys. 1988,88,7942. (8) Garrell, R. L.; Shaw, K. D.; Krimm, S. Surf. Sci. 1983,124,613. (9) Garrell, R. L.; Beer, K. D. Spectrochim. Acta Β 1988,435,617. (10) Liao, P. F.; Bergman, J. G.; Chemla, D. S.; Wokaun, Α.; Melngailis, J.; Hawryluk, A. M.; Economou, N. P. Chem. Phys. Lett. 1981,82,355. (11) Moody, R. L.; Vo-Dinh, T.; Fletcher, W. H. Appl. Spectrosc. 1987,41,966. (12) Cooney, R. P.; Mernagh, T. P.; Mahoney, M. R.; Spink, J. A. J. Phys. Chem. 1983,87,5314. (13) Stolberg, L.; Richer, J.; Lipkowski, J.; Irish, D. E. J. Electroanal. Chem. 1986, 207 213. (14) Vo-Dinh, T.; Hiromoto, M.Y.K.; Be gun, G. M.; Moody, R. I. Anal. Chem. 1984,56,1667. (15) Vo-Dinh, T.; Alak, Α.; Moody, R. L. Spectrochim. Acta Β 1988,43B, 605. (16) Alak, A. M.; Vo-Dinh, T. Anal. Chem. 1987,59,2149. (17) Carrabba, M. M.; Edmonds, R. B.; Rauh, R. D. Anal. Chem. 1987,59,2559. (18) Garrell, R. L.; Beer, K. D. Langmuir, in press. (19) Ahem, A. M.; Heme, T. M.; Garrell, R. L., manuscript in preparation. (20) Garrell, R. L.; Tanner, W.; Beer, K. D., submitted for publication in J. Elec troanal. Chem. (21) Kaul, B. B.; Holt, R. E.; Schlegel, V. L.; Cotton, T. M. Anal. Chem. 1988,60,1580. (22) Irish, D. E.; Stolberg, L.; Shoesmith, D. W. Surf. Sci. 1985, /58,238. (23) Dorain, P. B. J. Phys. Chem. 1986,90, 5808. (24) Niki, K.; Kawasaki, Y.; Kimura, Y.; Higuchi, Y.; Yasuoka, N. Langmuir 1987,3, 982. (25) Séquaris, J.-M.L.; Koglin, E. Anal. Chem. 1987,59, 527. (26) Ahem, A. M.; Garrell, R. L. Langmuir 1988,4,1162. (27) Cheng, Y-F; Dovichi, N. J. Science 1988,242, 562. (28) Freeman, R. D.; Hammaker, R. M.; Meloan, C. E.; Fateley, W. G. Appl. Spectrosc. 1988,42,456. (29) Forcé, R. K. Anal. Chem. 1988, 60, 1989. (30) Ahem, A. M.; Garrell, R. L. Anal. Chem. 1987,59, 2813. (31) Crookell, Α.; Fleischmann, M.; Hanniet, M.; Hendra, P. J. Chem. Phys. Lett. 1988 149 123 (32) Chase,' D. B.; Parkinson, B. A. Appl. Spectrosc. 1988,42,1186.
Moskovits, M. Rev. Mod. Phys. 1985, 57, 783. Seki, H. J. Electron Spectrosc. Relat. Phenom. 1986,39, 289. Weitz, D. Α.; Moskovits, M.; Creighton, J. A. In Chemical Structure at Interfaces; Hall, R. B.; Ellis, A. B., Eds.; VCH: Deerfield Beach, FL, 1986; Chapter 5, p. 197.
Robin L. Garrell received her B.S. Hon. degree in biochemistry from Cor nell University in 1978 and her Ph.D. in macromolecular science and engi neering from the University of Michi gan in 1984. She is an NSF Presiden tial Young Investigator. Her research involves using spectroscopic tech niques such as SERS to characterize protein-metal and polymer-metal in teractions and adsorption processes and designing polymer-modified sur faces. She is an avid squash player and photographer and has appeared as a guest chef on TV.
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Suggested reading Beer, K. D.; Tanner, W.; Garrell, R. L. J. Electroanal. Chem., in press. Cotton, T. M. In Spectroscopy of Surfaces; Clark, R.J.H.; Hester, R. E., Eds.; Wiley: New York, 1988; Chapter 3, p. 91. Creighton, J. A. In Spectroscopy of Sur faces; Clark, R.J.H.; Hester, R. E., Eds.; Wiley: New York, 1988; Chapter 2, p. 37. Gao, P.; Gosztola, D.; Leung, L.-W.H.; Weaver, M. J. J. Electroanal. Chem. 1987,233,211. Koglin, E.; Séquaris, J.-M. Top. Curr. Chem. 1986,134,1.
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ANALYTICAL CHEMISTRY, VOL. 61, NO. 6, MARCH 15, 1989 · 411 A