Mo-doped Co LDHs as Raman enhanced substrate for detection of roxarsine

Roxarsone (ROX) is widely used as a feed additive, which is indigestible after ingestion by poultry, and most of it can only be excreted into the natural environment and degraded into highly toxic and carcinogenic inorganic arsenic compounds, which pose a hazard to the ecosystem and human health. However, for roxarsone, traditional detection methods require complex and time-consuming procedures, so it is urgent to find a new fast detection method for detection of ROX.

In this work, we developed a novel Raman enhancement material and utilized the Surface-enhanced Raman scattering (SERS) technique to achieve rapid and sensitive detection of roxarsone. Specifically, Mo-doped cobalt layered double hydroxides (Co-LDHs) semiconductor material (abbreviated as CMM-100) was prepared by a simple method of using ion-assisted MOF etching. Under laser excitation at a wavelength of 532 nm, the CMM-100 showed excellent SERS property to various organic dye molecules such as methylene blue (MB), Toluidine Blue(TB), and Crystal Violet (CV). Especially, an enhancement factor (EF) of 1.4 × 10⁶ was achieved for MB. Compared with the traditional method, this work utilized the fast and non-destructive SERS technology, which achieved a rapid detection of ROX. The detection limit was as low as 9.73 × 10^-10 M, and the detection range was from 10^-9 M to 10^-3 M.

In this work, SERS technology was adopted for the rapid and sensitive detection of ROX. This study provides a Raman-enhanced substrate named CMMs for detection of food additives, pesticides, biomolecules, etc., which also broadens the application areas of SERS materials.