Abstract：
Nitrites are ubiquitous in food and pose a serious threat to human health. Therefore, the rapid and accurate determination of nitrite ion concentration in food is a prerequisite for eliminating the damage of nitrites. In this study, a robust, rapid, and sensitive method is proposed for nitrite detection in pickled food, in which Au@Ag nanoparticles are used as a reliable surface-enhanced Raman spectroscopy (SERS) substrate taking advantage of the high enhancement effect of silver and the good stability of gold. Nitrites were anchored to the surface of the SERS substrate by bridging with 4-aminophenylthiophenol (PATP). With Raman scattering cross-section amplification and internal calibration by PATP, a satisfactory linear relationship (R2 = 0.987) was established for nitrite detection in the concentration range of 5.00-100.00 μM, and the limit of detection (LOD) was 0.17 μM. This SERS-based method demonstrated high selectivity, good precision (RSD < 7.00 %), and satisfying recovery rates (101.42-107.35 %) in real samples, thus improving the determination method for nitrites. Therefore, this method has application potential in food safety and supervision.
摘要：
亚硝酸盐在食品中普遍存在，对人类健康构成严重威胁。因此,快速准确地测定食品中亚硝酸根离子浓度是消除亚硝酸盐危害的前提。在这项研究中,一个健壮的，快速,提出了腌制食品中亚硝酸盐的灵敏检测方法，其中Au@Ag纳米粒子作为一种可靠的表面增强拉曼光谱（SERS）基底，利用银的高增强作用和金的良好稳定性。通过与4-氨基苯基苯硫酚（PATP）桥接，将亚硝酸盐锚定在SERS底物的表面。通过拉曼散射截面放大和PATP内部校准，在5.00-707μM的浓度范围内,亚硝酸盐的检测具有良好的线性关系(R2=0.987),检测限(LOD)为0.17μM。这种基于SERS的方法显示出高选择性，良好的精度（RSD<7.00%），在实际样品中满足回收率(101.42-107.35%)，从而改进了亚硝酸盐的测定方法。因此,该方法在食品安全和监管方面具有应用潜力。
