Cu-BTC frameworks based electrochemical sensor for hazardous malachite green in aquaculture.

Malachite green (MG) has been widely used for controlling external fungi and parasites in the aquaculture. However, MG has been proven to be very hazardous, and the detection of MG in aquaculture environment is crucial for determining whether MG has been used within the allowed limit and for protecting the environment. Herein, a kind of copper based metal-organic frameworks (MOFs) was prepared using copper nitrate and 1,3,5-benzenetricarboxylic acid (H3BTC) as raw materials. The prepared Cu-BTC materials provide larger active area and higher accumulation capacity for MG, and meanwhile lower the charge-transfer resistance. As a result, the oxidation signal and detection sensitivity of MG are significantly improved by Cu-BTC frameworks. The linear range is 2-500 nM, and the detection limit is 0.67 nM, which is much lower than the reported values. Moreover, other usually-used aquaculture drugs have no interferences, including erythromycin, chloramphenicol, oxytetracycline, furazolidone and nitrofurazone. This method was applied in the water samples, and the results were consistent with those using high-performance liquid chromatography.