The use of surface-enhanced Raman scattering (SERS) for detecting domoic acid and saxitoxin was demonstrated and vibrational modes have been assigned based on the current literature. Silver nanoparticles were used to obtain the SERS spectra of domoic acid for the first time, which displayed enhancement of nearly 70 times the normal Raman spectra. Unique features in the SERS spectrum of domoic acid allowed the binding effect and orientation of the domoic acid to the metal surface to be analyzed. Saxitoxin exhibited an undetectable normal Raman signal but revealed very prominent SERS peaks. SERS peak positions closely matched published experimental and theoretical values, but with different peak ratios, indicating variance in molecule–nanoparticle interaction depending on the SERS substrate utilized. SERS is demonstrated as a powerful analytical tool for detecting toxins at low concentration with molecular specificity and shows immense potential for fast and remote sensing of toxins in various applications.
Vol. 6, Iss. 3 Virtual Journal for Biomedical Optics
Tammy Y. Olson, Adam M. Schwartzberg, Jinny L. Liu, and Jin Z. Zhang, "Raman and Surface-Enhanced Raman Detection of Domoic Acid and Saxitoxin," Appl. Spectrosc. 65, 159-164 (2011)