A novel label-free analytical strategy based on surface-enhanced Raman spectroscopy (SERS) has been developed for the detection of malachite green (MG) using spiky Fe3O4@Au supraparticles (Fe3O4@AuSPs). These supraparticles function dually as both concentrating probes and SERS-active substrates, leveraging the "built-in hotspots" at the tips of the spiky gold nanostructures and the magnetic aggregation effect of the core to achieve dual-signal amplification. Upon interaction with MG, the Fe3O4@AuSPs specifically capture the target analyte and exhibit strong SERS enhancement. Under the optimized conditions, the method achieved a limit of detection (LOD) as low as 10-12 M, with a linear range spanning from 10-4 to 10-11 M. It also demonstrated high specificity and was successfully applied to detect MG in real samples, including water from aquaculture systems and biological samples (fish, prawns, and crabs). This work provides a practical and efficient approach for MG monitoring in aquatic products, significantly reducing both detection time and cost, and exhibits strong potential for application in food safety surveillance.
Hang et al. (Thu,) studied this question.