Arsenic is an environmentally consequential metalloid which has various species based on its oxidation states and methyl substituents. In this study, Surface-Enhanced Raman Spectroscopy was utilized to explore Arsenic speciation under the cellular matrix influence using physiological buffers (sodium bicarbonate, phosphate etc.). Four common existing arsenicals were used: arsenite, arsenate, monomethylarsonic acid, and dimethylarsinic acid. Liquid droplets of arsenical solutions were dropped onto the Silver nanoparticle coated films and strong signals were generated by Raman spectroscopy. Signals were regenerated for the dried droplets after water evaporated from the solutions. Arsenicals were closer to the surface of the films and in the peripheral of the droplets after being dried. Vibrational bands were obtained in different intensities for the arsenicals and the data were analyzed for further evaluation. The significance of this project is to obtain detailed composition of Arsenic species in the biological matrix to evaluate its bioavailability and toxicity.
