An intelligent fluorescent nanoprobe (lignite-CDs-Eu) was constructed by an effective and facile method based on lignite-derived carbon dots (CDs) and lanthanide europium ions (Eu³⁺), which exhibited high sensitivity, low detection limit (13.35 nM) and visual color variation (from blue to red) under ultraviolet light towards tetracycline (TC) detection. Significantly, portable and economical sensors were developed using lignite-CDs-Eu immobilized fiber material of filter paper and wearable glove with the aid of color extracting and image processing application (APP) in the smartphone. Facile, fast and real-time visual detection of TC in food samples was realized. Moreover, logic gate circuit was also designed to achieve intelligent and semi-quantitative inspection of TC. To some extent, this study extended the cross-application of intelligent computer software in food analytical science, and provided a certain reference for the development of small portable detection sensors which were suitable for convenience and non-professional use in daily life.

Graphical abstract

中文翻译：

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基于便携式发光纤维和手套的纳米传感器，用于食品样品中四环素的多色视觉检测

^{基于褐煤衍生的碳点（CDs）和镧系铕离子（Eu 3+} ），通过有效且简便的方法构建了一种智能荧光纳米探针（褐煤-CDs-Eu），该探针具有高灵敏度、低检测限（13.35 nM） ）和紫外光下四环素（TC）检测的视觉颜色变化（从蓝色到红色）。值得注意的是，借助智能手机中的颜色提取和图像处理应用程序（APP），使用褐煤-CD-Eu固定纤维材料的滤纸和可穿戴手套开发了便携式且经济的传感器。实现了食品样品中TC的简便、快速、实时的视觉检测。此外，还设计了逻辑门电路，实现TC的智能化、半定量检测。该研究在一定程度上拓展了智能计算机软件在食品分析科学中的交叉应用，为开发适合日常生活中方便非专业使用的小型便携式检测传感器提供了一定的参考。

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