Measurement of Forchlorfenuron in Grapes by Surface - Enhanced Raman Spectroscopy coupled with Gold Nano substrates

The objective of this study was to use surface-enhanced Raman spectroscopy (SERS) for rapid detection and characterization of trace amounts of forchlorfenuron extracted from fruits. Forchlorfenuron is a plant growth regulator widely used in grapes and has negative effects on human health. In this study, gold-coated nanosubstrates were used for SERS measurements. Partial least squares (PLS) analysis was used as a statistical method for quantitative analysis of the spectral data. Our results demonstrate that enhanced Raman signals acquired from samples exhibited characteristic spectral patterns. The PLS results for quantification of forchlorfenuron were obtained: R=0.96, RMSEP=9.336×10-6. The detection limit for forchlorfenuron by SERS is 3.15ppm for pure forchlorfenuron solutions and 4.43 ppm for forchlorfenuron extracted from grape skin. In addition, HPLC was also used to measure forchlorfenuron and verify SERS results. A good linear relationship was observed between 0 - 100 ppm with an R value of 0.999. These results demonstrate that SERS coupled with gold nanosubstrates is a rapid and simple method and it requires little sample preparation. It could be a practical approach to combine SERS with HPLC method to screen and analyze food samples for chemical contaminants and residues.