The abuse of Penicillin G (PG) in the feeds of livestock resulted in health risk for human being via the food chain. It is urged to develop the rapid and sensitive method for monitoring PG residue in food products. In this work, silver shell was formed on the core gold nanoparticles protected with inositol hexaphosphate (IP₆), designated as Ag@IP₆@AuNPs, which is used as surface enhanced Raman scattering (SERS) substrate. Thanks to the presence of IP₆ between silver shell and core gold, Ag@IP₆@AuNPs show high storage stability. The great surface plasmon resonance of hot spot field generated in the molecular gap between core-shell extends to nanoparticle surface results in synergistic enhancement of Raman scattering effect. Ag@IP₆@AuNPs-based SERS assay is employed to successfully detect trace PG residue in milk with a wide linear quantitative range from 10⁻⁵ to 10^-11 mol/L and the limit of detection at 10^-12 mol/L. The sensitivity of such Raman protocol meets the requirement for the maximum residue limit (MRL, 4 μg/kg or 1.2 × 10⁻⁸ mol/L) of PG in milk products set by the European Union. Additionally, the detection recoveries in the range from 92.18 % to 101.4 % mean the acceptable robustness of such SERS method. The proposed SERS method could be advanced to realize the on-field determination of PG in milk for guarantee of food safety.

青霉素 G (PG) 在牲畜饲料中的滥用通过食物链对人类造成健康风险。敦促开发快速、灵敏的食品中PG残留监测方法。在这项工作中，银壳形成在用六磷酸肌醇 (IP ₆ )保护的核心金纳米粒子上，命名为 Ag@IP ₆ @AuNPs，用作表面增强拉曼散射 (SERS) 基底。由于银壳和核心金之间存在 IP ₆，Ag@IP ₆ @AuNPs 显示出很高的储存稳定性。核壳间分子间隙中产生的热点场的巨大表面等离子体共振延伸到纳米颗粒表面，导致拉曼散射效应的协同增强。银@IP₆基于@AuNPs 的SERS 分析成功地检测了牛奶中的痕量PG 残留，线性定量范围从10 ^-5到10 ^-11 mol/L，检测限为10 ^-12 mol/L。这种拉曼方案的灵敏度符合欧盟对乳制品中PG的最大残留限量（MRL，4 μg/kg或1.2 × 10 ^-8 mol/L）的要求。此外，在 92.18% 至 101.4% 范围内的检测回收率意味着此类 SERS 方法具有可接受的稳健性。所提出的 SERS 方法可用于实现牛奶中 PG 的现场测定，以保证食品安全。