Rapid detection of malachite green residues in fish using a surface-enhanced Raman scattering-active glass fiber paper prepared by in situ reduction method.

Food safety issues, especially those related to drug residues, have caused concern in recent years. Malachite green (MG), which is frequently used as ectoparasiticide, fungicide, and antiseptic in fish farming, is poisonous and carcinogenic. Several technologies and methods have been developed to accurately detect MG, but they can be time-consuming and expensive. Herein, we prepared a glass fiber paper as a surface-enhanced Raman scattering substrate for rapid and convenient detection of MG residues in fish. Uniform silver nanoparticles were deposited on the glass fiber paper by two in situ reduction steps of silver nitrate. The Raman signal of MG was detected and recorded using a portable Raman spectrometer in 10 s. There was a good linear relationship between the surface-enhanced Raman scattering signal intensity and the concentration of MG between 1 × 10-7 and 1 × 10-5 mol/L and the limit of detection was 5 × 10-10 mol/L. Residual MG in fish samples was extracted and detected with a recovery rate range of 98.9-119.4%. This method provides a novel way to detect MG in fish.