Rapid detection of malachite green in fish and water based on the peroxidase-like activity of Fe3O4NPs enhanced with aptamer

This study attempted to fabricate a novel colorimetric method for the quantitative detection of malachite green (MG) residues in fish and water samples. Based on the recognition of the detection target and the enhancement of the peroxidase-like activities of Fe 3 O 4 NPs by MG-aptamer, a colorimetric method was established for MG detection. The detection limit (3 α / κ , n = 9) was 16.7 μg kg –1 , and the detection linear range was 0.06–2.38 μmol L –1 . The recovery rates by standard addition in fish and water ranged from 90.1% to 119% with standard deviations (n = 3) of less than 6.6 %, and was well validated by a HPLC method. The detection procedure could be completed within 1 h. Therefore, the detection method was simple, stable, and reliable, and could be used to detect MG residues rapidly and accurately in fish and aquaculture water.