Abstract Owing to the great role of glucose in biological systems and food industry, it is significant to maintain the dynamic balance of organisms. Various methods widely reported are focused on the glucose detection with high sensitivity and low detection limit. However, the sensor with ultra-low concentration sensitivity is not suitable for the direct detection of high concentration of glucose in human serum and food samples. Additionally, the application of ratiometric fluorescence probe is usually limited by the narrow range of color changes and insensitivity color change of the target. Here, a novel dual-emission ratiometric fluorescence probe with green to red fluorescence intensity of 6:1 was first constructed by fluorescein isothiocyanate (FITC) with green fluorescence as signal unit and silica coated quantum dot (QD@SiO2) with red fluorescence as the stable internal standard. The glucose was oxidized to generate H2O2 by the catalysis of glucose oxidase, which can oxidize Fe2+ to form Fe3+ ion. The formation of Fe3+ ion will cause the quenching of FITC fluorescence, which can realize the continuous fluorescence color change from green to yellow to orange to red for the qualitative and quantitative detection of blood glucose and fruit juice. The proposed method is cheap, simple, intuitive and has a wide detection range for glucose detection, which is of significance in designing the dual-emission ratiometric fluorescence sensor with wide range of color change.

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基于电子转移机制的葡萄糖剂量敏感视觉识别比例荧光纳米传感器

摘要 由于葡萄糖在生物系统和食品工业中的重要作用，维持生物体的动态平衡具有重要意义。广泛报道的各种方法都集中在具有高灵敏度和低检测限的葡萄糖检测上。然而，超低浓度灵敏度的传感器不适合直接检测人血清和食品样品中的高浓度葡萄糖。此外，比率荧光探针的应用通常受到目标颜色变化范围窄和不敏感颜色变化的限制。在这里，一种新型的双发射比例荧光探针，绿到红荧光强度为 6：1首先由以绿色荧光为信号单元的异硫氰酸荧光素（FITC）和以红色荧光为稳定内标的二氧化硅包覆量子点（QD@SiO2）构建而成。葡萄糖在葡萄糖氧化酶的催化下被氧化生成H2O2，H2O2可以氧化Fe2+形成Fe3+离子。Fe3+离子的形成会引起FITC荧光的猝灭，可以实现荧光颜色从绿色到黄色到橙色到红色的连续变化，用于血糖和果汁的定性和定量检测。该方法廉价、简单、直观，对葡萄糖检测具有较宽的检测范围，这对于设计具有宽范围颜色变化的双发射比率荧光传感器具有重要意义。葡萄糖在葡萄糖氧化酶的催化下被氧化生成H2O2，H2O2可以氧化Fe2+形成Fe3+离子。Fe3+离子的形成会引起FITC荧光的猝灭，可以实现荧光颜色从绿色到黄色到橙色到红色的连续变化，用于血糖和果汁的定性和定量检测。该方法廉价、简单、直观，对葡萄糖检测具有较宽的检测范围，这对于设计具有宽范围颜色变化的双发射比率荧光传感器具有重要意义。葡萄糖在葡萄糖氧化酶的催化下被氧化生成H2O2，H2O2可以氧化Fe2+形成Fe3+离子。Fe3+离子的形成会引起FITC荧光的猝灭，可以实现荧光颜色从绿色到黄色到橙色到红色的连续变化，用于血糖和果汁的定性和定量检测。该方法廉价、简单、直观，对葡萄糖检测具有较宽的检测范围，这对于设计具有宽范围颜色变化的双发射比率荧光传感器具有重要意义。可实现由绿变黄、橙变红的连续荧光颜色变化，用于血糖和果汁的定性定量检测。该方法廉价、简单、直观，对葡萄糖检测具有较宽的检测范围，这对于设计具有宽范围颜色变化的双发射比率荧光传感器具有重要意义。可实现由绿变黄、橙变红的连续荧光颜色变化，用于血糖和果汁的定性定量检测。该方法廉价、简单、直观，对葡萄糖检测具有较宽的检测范围，这对于设计具有宽范围颜色变化的双发射比率荧光传感器具有重要意义。