Peroxidase-like recyclable SERS probe for the detection and elimination of cationic dyes in pond water

Highlights: • Ni@Mil-100(Fe)@Ag nanowires are successfully fabricated based on prickly Ni nanowires and Mil-100(Fe). • This probe exhibits excellent peroxidase-like activity and adsorption capability for recyclable SERS detection. • This probe is suitable for selective detection and elimination of multiple illegal fishery drugs in pond water. A peroxidase-like MOF coated magnetic surface-enhanced Raman scattering (SERS) probe as Ni@Mil-100(Fe)@Ag nanowires (NMAs) was developed, which can detect multiple cationic dyes with a good recyclability and a high sensitivity. Specifically, Mil-100(Fe) with peroxidase-like activity was fabricated on the magnetic prickly Ni nanowires through layer-by-layer (LBL) method. With the presence of 10 mM H₂O₂, hydroxyl radical (• OH) produced by peroxidase-like catalytic reaction of Mil-100(Fe) layer can easily eliminate the pollution molecules within 1 min without any requirement for expensive equipment or complicated process. The magnetic NMAs can provide a rapid refreshment for at least 10 times. In addition, carboxyl-functionalized Mil-100(Fe) can not only increase the decoration efficiency of Tollens but also promote the selective enrichment of the cationic dyes, which endows the probe with a greatly improved sensitivity with a limit of detection (LOD) as low as 10⁻¹⁰ M for crystal violet (CV). Following the erasure by H₂O₂, multiple cationic fishery drugs in pond water can be sequentially detected. Such a recyclable SERS probe holds a great potential in various applications as aquaculture, biomedicine and chemical analysis.