Fast detection of saxitoxin using laser tweezers surface enhanced Raman spectroscopy

Abstract

Saxitoxin (STX) is a potent marine biotoxin which can cause paralytic shellfish poisoning when consumed. With the development of research, STX has become more and more important in red tide detection, medical research, food safety and warfare agent application. However, new methods for the fast analysis of STX are required. In this study, we used laser optical tweezers Raman spectroscopy (LTRS) combined with surface-enhanced Raman scattering (SERS) to detect STX. Sharp Raman peaks of very strong intensity were achieved. The spectra were obtained in 2 seconds without accumulations. Tentative vibrational mode assignments of the observed peaks in SERS spectra of STX are described. The detection limit and the minimum quantitative limit of this method were 2 nM and 16 nM, respectively. This study supports LTRS-SERS as a new fast, convenient analytical method for STX and other toxicants and pollutants in the environment.