Decomposition of Amino Acids Catalyzed by Plasmonic Gold Nanoparticles

Gold nanoparticles (AuNPs) are known catalytically active in many reactions such as CO/NO oxidation and selective oxidation of benzaldehyde. However, very few studies have been devoted to understanding how AuNPs catalyze reactions of biorelated molecules such as amino acids absorbed on their surface even though AuNPs have found broad biomedical applications. Herein, we report that AuNPs can behave like some enzymes in nature, catalyzing the decomposition of glycine into cyanide at ambient conditions. Highly sensitive surface enhanced Raman scattering (SERS) spectroscopy was used to probe this decomposition reaction at the chemical level. In addition, the excitation of surface plasmons was also found to further enhance this catalytic process. Not limited to glycine, other amino acids such as alanine and asparagine can also be decomposed into cyanide under the same conditions, suggesting that gold nanocatalysis on the decomposition et amino acids is a general phenomenon.