Surface-enhanced Raman spectra of dimethoate and omethoate
Article first published online: 4 NOV 2010
Copyright © 2010 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Volume 42, Issue 5, pages 980–985, May 2011
How to Cite
Guerrini, L., Sanchez-Cortes, S., Cruz, V. L., Martinez, S., Ristori, S. and Feis, A. (2011), Surface-enhanced Raman spectra of dimethoate and omethoate. J. Raman Spectrosc., 42: 980–985. doi: 10.1002/jrs.2823
- Issue published online: 20 MAY 2011
- Article first published online: 4 NOV 2010
- Manuscript Accepted: 17 SEP 2010
- Manuscript Received: 5 MAY 2010
- surface-enhanced Raman;
- pesticide analysis;
- silver hydrosols
Surface-enhanced Raman scattering (SERS) spectra are presented and analyzed for two important organophosphate pesticides, dimethoate (DMT) and omethoate (OMT). Very detailed SERS spectra were obtained by aggregated Ag hydrosols, both in aqueous suspension and dried on a glass substrate. The SERS and ordinary Raman spectra of DMT do not resemble each other, suggesting that a chemical reaction immediately occurs when DMT is adsorbed onto the metal surface. We propose that the reaction product is OMT, which is the oxygen analog of DMT, on the basis of the Raman and SERS spectra of OMT. Further support is derived from the calculated Raman spectra of DMT and OMT. Minor wavenumber and intensity differences that are observed between the SERS spectra of DMT reaction product and those of OMT could be related to different metal/adsorbate interaction modes. The results can be useful in the development of new analytical methods for the determination of pesticide residues in food. Copyright © 2010 John Wiley & Sons, Ltd.