Rapid detection method of malachite green in water body

The invention discloses a rapid detection method of malachite green in a water body. The method comprises the following steps: 1) malachite green standard samples with a series of concentrations are respectively mixed with silver-coated magnetic beads such that malachite green is adsorbed on the silver-coated magnetic beads, and the silver-coated magnetic beads are collected by a magnetic field; 2) surface-enhancement Raman scattering measurement is carried out on the silver-coated magnetic beads collected in the step 1), and a standard curve between malachite green concentration and Raman signal intensity is drawn; and 3) a sample to be tested is processed successively according to the step 1) and the step 2), Raman signal intensity of the sample to be tested is measured, and the Raman signal intensity is introduced into the standard curve obtained in the step 2) so as to obtain malachite green concentration of the sample to be tested. By using the silver-coated magnetic beads as a SERS enhanced substrate, quantitative analysis of trace amount of malachite green in a water body is realized. The method is convenient to operate, has low limit of detection, is accurate and rapid and can be directly used in detecting malachite green in an actual water sample.