Simultaneous detection of two pesticide residues in tobacco leaves using SiO2@Ag-SERS substrate and portable Raman spectrometer

Surface-enhanced Raman spectroscopy (SERS) has great potential for rapid detection of trace levels of pesticides in food. Scientists have much interested in this analytical technique due to its sensitivity, rapid detection, simplicity, and low cost. However, most of researchers are only focusing on the detection of a single pesticide residue. In this paper, we firstly report the simultaneous detection of two pesticide residues in tobacco leaves by using composite SERS substrate of SiO2@Ag nanoparticles. The entire analysis time is less than 10 min. The detection results show satisfactory linearity in the range of 0.1–25 mg/kg and 1–25 mg/kg with the limit of detection of 0.1 mg/kg and 1 mg/kg for carbendazim and flumetralin in tobacco samples, respectively. The recovery rates of carbendazim and flumetralin in the tobacco leaves are 85.2 ∼ 112.12 % and 90.38 ∼ 113.42 %, respectively. The detection results also show good uniformity and reproducibility, with a relative standard deviation(RSD) value of 4.4 % between substrates. Our reported substrate combined with portable Raman spectrometer provides a powerful tool for simultaneous detection of multiple pesticide residues for food safety.