Detection of forchlorfenuron in grapes by surface-enhanced raman spectroscopy and HPLC

Abstract

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. In this study, gold-coated nanosubstrates (Q-SERSTM) 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 detection limit for forchlorfenuron by SERS is 3.14 ppm at 99.86% confidence interval. The PLS results for quantification of forchlorfenuron were obtained: R = 0.96, RMSEP = 9.336 ppm. In addition, HPLC was also used to measure forchlorfenuron and verify SERS results. A good linear relationship was observed between 0.1 - 100 ppm with an R value of 0.999 at 260 nm. These results demonstrate that SERS coupled with gold nanosubstrates is a rapid and simple method that requires little sample preparation. It could be a practical and economical approach to combine SERS with HPLC to screen and analyze large number of food samples for detecting chemical contaminants and residues in fruits.