PDF(Pubmed)
Abstract：
Total volatile basic nitrogen (TVB-N) is a vital indicator for assessing seafood freshness and edibility. Rapid on-site detection of volatile basic nitrogen (VBN) is of significant importance for food safety monitoring. In this study, highly luminescent self-assembled copper nanoclusters (Cu NCs@p-MBA), synthesized using p-mercaptobenzoic acid (p-MBA) as the ligand, were utilized for the sensitive detection of VBNs. Under acidic conditions, Cu NCs@p-MBA formed compact and well-organized nanosheets through noncovalent interactions, accompanied by intense orange fluorescence emission (651 nm). The benzene carboxylic acid part of Cu NCs@p-MBA provided the driving force for supramolecular assembly and exhibited a strong affinity for amines, particularly low-molecular-weight amines such as ammonia (NH3) and trimethylamine (TMA). The quantitative determination of NH3 and TMA showed the detection limits as low as 0.33 and 0.81 ppm, respectively. Cu NCs@p-MBA also demonstrated good responsiveness to putrescine and histamine. Through density functional theory (DFT) calculations and molecular dynamics (MD) simulations, the precise atomic structure, assembly structure, luminescent properties, and reaction processes of Cu NCs@p-MBA were studied, revealing the sensing mechanism of Cu NCs@p-MBA for highly sensitive detection of VBNs. Based on the self-assembled Cu NCs@p-MBA nanosheets, portable fluorescent labels were developed for semiquantitative, visual, and real-time monitoring of seafood freshness. Therefore, this study exemplified the high sensitivity of self-assembly induced emission (SAIE)-type Cu NCs@p-MBA for VBNs sensing, offering an efficient solution for on-site monitoring of seafood freshness.
摘要：
总挥发性碱性氮（TVB-N）是评估海鲜新鲜度和可食性的重要指标。挥发性碱性氮（VBN）的快速现场检测对于食品安全监测具有重要意义。在这项研究中,高发光自组装铜纳米簇(CuNCs@p-MBA)，以对巯基苯甲酸（p-MBA）为配体合成，用于VBN的灵敏检测。在酸性条件下,CuNCs@p-MBA通过非共价相互作用形成紧凑且组织良好的纳米片，伴随着强烈的橙色荧光发射（651nm）。CuNCs@p-MBA的苯羧酸部分提供了超分子组装的驱动力，并表现出对胺类的强亲和力，特别是低分子量胺,如氨(NH3)和三甲胺(TMA)。NH3和TMA的定量测定显示检出限低至0.33和0.81ppm，分别。CuNCs@p-MBA对腐胺和组胺也表现出良好的反应性。通过密度泛函理论(DFT)计算和分子动力学(MD)模拟,精确的原子结构，装配结构,发光性能，并研究了CuNCs@p-MBA的反应过程，揭示了CuNCs@p-MBA对VBN高灵敏度检测的传感机理。基于自组装的CuNCs@p-MBA纳米片，便携式荧光标签被开发用于半定量，视觉，和实时监测海鲜新鲜度。因此,这项研究举例说明了自组装诱导发射（SAIE）型CuNCs@p-MBA对VBN传感的高灵敏度，为现场监测海鲜新鲜度提供有效的解决方案。
