Pu Zixuan, Li Kuan, Fan Wenlin, Wang Ying, Xiao Lili, Li Mingtian
School of Materials Science and Engineering, Sichuan University of Science and Engineering, Zigong, 643000, China.
Materials Corrosion and Protection Key Laboratory of Sichuan Province, Zigong, 643000, China.
J Fluoresc. 2024 Aug 13. doi: 10.1007/s10895-024-03892-6.
Carbon quantum dots are a new type of fluorescent carbon-based nanomaterials, and their excellent properties have provoked a strong research interest. Herein, blue-fluorescent carbon quantum dots (k-CQDs) were successfully synthesized by a simple one-step hydrothermal method using chitosan and ethylenediaminetetraacetic acid as precursors. It was found that Fe could quench the fluorescence of k-CQDs by a dynamic quenching mechanism that increased the positive charge in solution. Due to ascorbic acid (AA) can reduce Fe to Fe, the positive charge in solution was reduced and the fluorescence of k-CQDs was restored. Based on the mechanism of the fluorescence "on-off-on", k-CQDs were used for the detection of Fe and AA with strong antijamming capability. The LOD for Fe concentrations in the ranges of 0 to 30 µM and 30 to 100 µM were 0.3 µM and 0.76 µM, respectively. The LOD for AA concentrations in the ranges of 0 to 82.5 µM and 82.5 to 172.5 µM were 3.93 µM and 1.63 µM, respectively. Spiking recoveries of Fe in tap water, AA in orange juice and tomato juice were 87.93 ∼ 101.13%, 86.77 ∼ 105.15% and 86.43 ∼ 103.80%, respectively. Meanwhile, k-CQDs also showed good potential for anti-counterfeiting encryption.
碳量子点是一类新型的荧光碳基纳米材料，其优异性能引发了强烈的研究兴趣。在此，以壳聚糖和乙二胺四乙酸为前驱体，通过简单的一步水热法成功合成了蓝色荧光碳量子点（k-CQDs）。研究发现，Fe可通过增加溶液中正电荷的动态猝灭机制猝灭k-CQDs的荧光。由于抗坏血酸（AA）能将Fe还原为Fe，溶液中的正电荷减少，k-CQDs的荧光得以恢复。基于荧光“开-关-开”机制，k-CQDs用于检测Fe和AA，具有较强的抗干扰能力。Fe浓度在0至30 μM和30至100 μM范围内的检测限分别为0.3 μM和0.76 μM。AA浓度在0至82.5 μM和82.5至172.5 μM范围内的检测限分别为3.93 μM和1.63 μM。自来水中Fe、橙汁和番茄汁中AA的加标回收率分别为87.93%至101.13%、86.77%至105.15%和86.43%至103.80%。同时，k-CQDs在防伪加密方面也显示出良好的潜力。
