Simple Synthesis of Cellulose-Based Nanocomposites as SERS Substrates for In Situ Detection of Thiram.

There is a growing interest in the use of flexible substrates for label-free and in situ Surface-enhanced Raman Spectroscopy (SERS) applications. In this study, a flexible SERS substrate was prepared using self-assembled Au/TiC nanocomposites deposited on a cellulose (CS) paper. The Au/TiC nanocomposites uniformly wrapped around the cellulose fibers to provide a three-dimensional plasma SERS platform. The limit of detection (LOD) of CS/Au/TiC was as low as 10 M for 4-mercaptobenzoic acid(4-MBA) and crystal violet (CV), demonstrating good SERS sensitivity. CS/Au/TiC was used for in situ SERS detection of thiram on apple surfaces by simple swabbing, and a limit of detection of 0.05 ppm of thiram was achieved. The results showed that CS/Au/TiC is a flexible SERS substrate that can be used for the detection of thiram on apple surfaces. These results demonstrate that CS/Au/TiC can be used for the non-destructive, rapid and sensitive detection of pesticides on fruit surfaces.