A highly sensitive surface-enhanced Raman scattering sensor with MIL-100(Fe)/Au composites for detection of malachite green in fish pond water.

Concerns about food safety have been arisen due to the improper use of chemicals in aquaculture. Malachite green (MG) has attracted attention because of its illegal usage and its potential negative impacts on the environment and public health. Surface-enhanced Raman scattering (SERS) platforms coupled with different SERS substrates have been employed for rapid analysis of MG residues in food. However, the most commonly used SERS substrates were non-reusable and showed limited detection sensitivity. In this study, a novel SERS substrate with a good recyclability and a high sensitivity was prepared by electrostatically assembling together a metal-organic framework material called materials of institute lavoisie-100(Fe) (MIL-100(Fe)) and Au NPs. The lowest detectable concentration of MG was 10-13 M based on the optimal substrate. The SERS sensor was applied for the detection of the trace MG in fish pond water, which was accomplished with the correlation coefficients R2 = 0.991-0.996 in a concentration range of 10-6-10-13 M. Moreover, MIL-100(Fe)/Au was recycled at least five times, realizing a "detection to degradation", showing great potential for food contamination monitoring due to its distinguished performance.