Ag Nanoparticles Meet Wines: SERS for Wine Analysis

摘要: The interface between the silver nanoparticles (AgNPs) obtained by classical wet method and red or white wines has been explored using surface-enhanced Raman scattering technique (SERS), aiming to assess capability for providing direct spectral biomarkers of wines. Regardless wine color, their normal excited with visible laser lines showed strong fluorescence signal superimposed main bands attributable alcohol water, which drastically hamper component detection discrimination without additional chemometrics. observed SERS in 532 nm are likely associated SE(R)RS effect anthocyanin pigments absorb this line, while enhancement other flavonoids is co-existent resulted background. Moreover, possessing large number hydroxyl groups molecular structure being pH-sensitive alkaline environment, undergo changes like auto-oxidation, dimerization, polymerization. Adding small amount AgNPs, provides environment (pH 7.5) a ratio 1:50 v/v wine:AgNPs, results instant NP aggregation flavonoid adsorption on AgNPs. strength complex process essentially dependent content, balance water ethanol (which also an intrinsic characteristic each reason dependencies), pH defines its acidity). Thus, pilot study established optimal approach great promise extended applications fast monitoring, substantial advantages over current agreed techniques.