Abstract：
Poisonous histamine is accumulated in stale meat and fermented foods. The rapid and stable detection of histamine is essential for food safety. Herein, a ratiometric fluorometric method for histamine detection was designed through in situ preparing double-stranded DNA‑copper nanoclusters (dsDNA-Cu NCs) stained with 4\',6-diamidino-2-phenylindole (DAPI). dsDNA-Cu NCs with red emission were rapidly synthesized via mixing Cu2+, ascorbate and dsDNA at room temperature for 5 min. When DAPI was added during preparation, DAPI coordinated with the Cu element accompanied by the quenched red emission of dsDNA-Cu NCs, and DAPI bound to dsDNA together with the enhanced blue emission of DAPI. Upon adding DAPI and histamine simultaneously, the coordination of histamine with the Cu element further decreased the red emission of dsDNA-Cu NCs, and drove the movement of DAPI from the Cu element to dsDNA along with the enhanced blue emission of DAPI. Significantly, ratiometric fluorescence was insensitive to variations in instrument and environment, causing stable measurement. Meanwhile, in situ synthesis integrated probe preparation with analyte detection, reducing time consumption. Additionally, this method quantified histamine in the concentration range of 7-50 μM with a detection limit of 3.6 μM. It was applied to determining histamine in food with satisfactory accuracy and precision.
摘要：
有毒组胺积累在陈旧的肉类和发酵食品中。组胺的快速稳定检测对食品安全至关重要。在这里，通过原位制备4'染色的双链DNA-铜纳米簇（dsDNA-CuNCs），设计了用于组胺检测的比率荧光法，6-二氨基-2-苯基吲哚(DAPI)。通过混合Cu2+快速合成具有红色发射的dsDNA-CuNCs，抗坏血酸和dsDNA在室温下5分钟。当在制备过程中添加DAPI时，DAPI与Cu元素协调，伴随着dsDNA-CuNCs的猝灭红色发射，和DAPI与dsDNA结合,同时DAPI的蓝色发射增强。同时添加DAPI和组胺后，组胺与Cu元素的配位进一步降低了dsDNA-CuNCs的红色发射，并推动DAPI从Cu元素向dsDNA的移动，同时DAPI的蓝色发射增强。重要的是,比率荧光对仪器和环境的变化不敏感，造成稳定的测量。同时,原位合成集成探针制备与分析物检测，减少时间消耗。此外,该方法定量组胺的浓度范围为7-50μM，检出限为3.6μM。该方法用于食品中组胺的测定，具有良好的准确度和精密度。
