“Switch-On” Fluorescent Sensing of Ascorbic Acid in Food Samples Based on Carbon Quantum Dots–MnO2 Probe

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• 作者：Juanjuan Liu ; Yonglei Chen ; Weifeng Wang ; Jie Feng ; Meijuan Liang ; Sudai Ma ; Xingguo Chen
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2016
• 出版时间：January 13, 2016
• 年：2016
• 卷：64
• 期：1
• 页码：371-380
• 全文大小：572K
• ISSN：1520-5118

文摘

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.