Rapid detection of pesticide residues in foods using surface-enhanced raman spectroscopy coupled with gold nanostars

Abstract

Constant monitoring pesticide residues in foods is an essential part of food safety. In recent years, there is a growing concern about food issues in agricultural products. Tradition testing methods such as high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) demand time-consuming sample preparations and well-trained operators. Therefore, this research aimed to establish a novel, simple, and rapid testing technique. In this study, the SERS performance of gold nanostars was evaluated by detecting two commonly used pesticides, thiabendazole (TBZ) and paraquat in the real food samples. Gold nanostars were used as a surface-enhanced Raman spectroscopy (SERS) substrate due to their highly branched structure, which provide many SERS hot spots for generating intensified Raman signals from the target analytes. Additionally, the rough topography of gold nanostars has large surface area, which can enable good interactions between the substrate and analyte molecules. The UV-vis spectrometer, electron microscopes and Zetasizer were utilized for characterization. The detection limits of this SERS method are 5 ppm for TBZ in apple juice and 0.2 ppm for paraquat in green tea. These results indicate that SERS coupled with gold nanostars is a facile approach and has great potential to be applied for qualification and quantification of trace contaminants in foods.