Food Quality Monitoring Based on Hydrolysis-Induced Au-Catalyzed Heck Cross-Coupling by Ag Metallization

Visual detection of meat spoilage was performed based on hydrolysis-induced silver metallization on gold nanoparticles (Au NPs). The hydrolysis of 4-I-benzene-bounded Wang resin was induced by the release of a biogenic amine followed by Au-catalyzed Heck cross-coupling reaction that made silver-coated gold core-shell NPs (Au@Ag) in the presence of Ag ions (Ag metallization). A portable sensory cap was designed by this hypothesis and the successful results were obtained for histamine, trimethylamine, and a spoilage sheep meat. With this protocol, the localized surface plasmon resonance (LSPR) is tuned for absorption of Au NPs and leads to LSPR peak blue shift of gold nanoparticles due to the Ag metallization and the preparation of Au@Ag core-shell NPs. Au NPs and the resulting Au@Ag NPs were characterized by transmission electron microscopy (TEM), BET, ultraviolet-visible (UV-Vis), X-ray diffraction (XRD), energy dispersive X-ray (EDX), and dynamic light scattering (DLS) analyses. Also, various control experiments were set up to credit the portable sensory tube.