Unraveling the protein corona formation during the surface-enhanced Raman spectroscopy detection of malachite green in fish.

Abstract

In surface-enhanced Raman spectroscopy (SERS) detection of drug residues, food matrices, especially the protein corona around nanomaterials, pose challenges to accurate detection. This study used sea bass, a fish product with a complex matrix, and malachite green as a target fish drug to investigate these effects. Multiple techniques were used to elucidate the interactions among proteins, malachite green, and gold nanoparticles (AuNPs). The detection limit of malachite green in fish extract (740 μg/L) was much higher than in standard solutions (0.42 μg/L). At a protein concentration of 0.5 mg/mL, a uniform protein corona formed around the AuNPs, resulting in an aggregation-sedimentation rate of 9.23 %. Malachite green adsorption by AuNPs decreased by 99 % after protein corona formation. The work reveals how protein corona affects SERS detection of fish drugs, guiding development of signal regulation strategies for enhanced SERS sensitivity in food safety.