基于石墨烯量子点(GQDs)的荧光性能建立了一种非标记荧光方法,用于灵敏和选择性测定抗坏血酸(AA)。 GQDs 溶液在紫外光激发下发出很强的蓝色荧光,当向溶液中加入 AA 后,GQDs 溶液的荧光被猝灭。猝灭机理可能为在弱酸性介质中,AA 与 GQDs 发生氧化还原反应,AA 转移电子给 GQDs。荧光猝灭强度与AA 浓度在5.0×10-6~7.5×10-5 mol／ L 范围内呈良好的线性关系,检出限低至1.0×10-6 mol／ L。该体系成本低、操作简单,并且在多种可能干扰的物质存在下对 AA 表现出很高的选择性。本方法应用于生物样品中AA 的检测,回收率在95.2％~115.3％之间。%A label-free fluorescence method based on the fluorescence property of graphene quantum dots (GQDs) was developed for sensitive and selective detection of ascorbic acid (AA). The initial strong blue fluorescence of the GQDs in aqueous solution was effectively quenched upon addition of AA. The quenching mechanism may involve transfer of electrons from AA to GQDs via the redox re-action of AA and GQDs in weak acid solution. The quenching efficiency was linearly proportional to the concentration of AA within the range of 5. 0 × 10 - 6 - 7. 5 × 10 - 5 mol/ L with a low detection limit down to 1. 0 × 10 - 6 mol/ L. The proposed sensing system is simple and low-cost with facile experi-mental operations, and has a high selectivity for AA over a number of possible interfering species. Additionally, this method was successfully applied to the determination of AA in biological samples with satisfactory recoveries (95. 2% - 115. 3% ).
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