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.