State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University , Lanzhou 730000, China.
Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University , Lanzhou 730000, China.
J Agric Food Chem. 2016 Jan 13;64(1):371-80. doi: 10.1021/acs.jafc.5b05726. Epub 2015 Dec 22.
This work describes a "switch-on" fluorescence approach for sensing of ascorbic acid (AA) in food samples. In the present method, the fluorescence intensity (FL) of carbon quantum dots (CQDs) was first quenched by addition of MnO2 nanosheets through an inner filter effect to form a CQDs-MnO2 probe. When reductive AA was introduced into the quenched CQDs solution, the added MnO2 was destroyed due to the redox reaction between AA and MnO2 nanosheets, and the FL of the system was recovered. Under the optimal conditions, the limit of detection for AA was 42 nM, with a wide concentration linear range of 0.18-90 μM. Furthermore, the as-fabricated fluorescent sensing system was successfully applied to the analysis of AA in fresh fruits, vegetables, and commercial fruit juices samples with satisfactory results.
本工作描述了一种用于检测食品样品中抗坏血酸 (AA) 的“开启”荧光方法。在本方法中，通过内滤效应将 MnO2 纳米片添加到碳量子点 (CQDs) 中，首先猝灭 CQDs 的荧光强度 (FL)，以形成 CQDs-MnO2 探针。当将还原性 AA 引入猝灭的 CQDs 溶液中时，由于 AA 和 MnO2 纳米片之间的氧化还原反应，添加的 MnO2 被破坏，并且该体系的 FL 得到恢复。在最佳条件下，AA 的检测限为 42 nM，具有 0.18-90 μM 的宽浓度线性范围。此外，所构建的荧光传感系统成功地应用于新鲜水果、蔬菜和商业果汁样品中 AA 的分析，结果令人满意。
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