Strategy on effective detection of acetaldehydes by using surface-enhanced Raman scattering-active chitosan-capped nanostructured Au

According to materials safety and data sheets (MSDS) acetaldehyde is a toxic and cancer-induced reagent. Its presence in spirits can cause damage to livers of drinkers. Conventionally, the concentration of acetaldehyde is measured by using gas chromatography–mass spectrometer (GC–MS). Development of new analytical technology for detecting acetaldehyde would be contributive to human healthy. In this work, we report an innovative idea to prepare functionalized surface-enhanced Raman scattering (SERS)-active chitosan (Ch)-capped nanostructured Au (NSAu) by using electrochemical oxidation–reduction cycles (ORC) for concentrating and detecting acetaldehyde in solutions. Because the capping reagents of Ch are SERS-inactive the SERS intensity of model probing molecules of rhodamine 6G (R6G) adsorbed on Ch-capped NSAu is expectedly reduced, as compared with that adsorbed on NSAu. However, acetaldehyde can react with Ch on Ch-capped nanostructured Au to yield a Schiff base. It is encouragingly found that SERS intensity of acetaldehyde adsorbed on Ch-capped NSAu is markedly increased, as compared with that adsorbed on NSAu. It indicates that the developed SERS-active substrate is enough efficient for the detection of acetaldehyde.