为了研究氮掺杂对纳米碳点荧光发射行为的影响和探索掺氮碳点的快速制备途径, 以2-氨基对苯二甲酸为前驱体, 与不同的修饰剂一起溶解于去离子水中, 经微波辐射3 min, 一步法合成了新型掺氮碳点。实验结果表明: 制备的掺氮碳点水溶性好, 发蓝色荧光, 且发射行为不依赖于激发波长; 颗粒近似为球形, 尺寸5～8 nm, 晶面间距为0.23 nm, 接近石墨碳(100)面晶格结构; Fe3+通过与掺氮碳点表面含氧基团的络合配位, 可有效地猝灭其荧光, Fe3+浓度在5～60 μmol·L-1的范围内与相对荧光强度呈现良好的线性关系, 检出限约为1.01 μmol·L-1, 可以作为检测Fe3+浓度的荧光探针。

In order to study the impact of nitrogen-doping on the photoluminescence properties of carbon nanodots and explore a facile preparing approach for nitrogen-doping carbon dots(N-CDs), 2-aminoterephthalic acid as the precursor and various modifiers were firstly dissolved in deionized water. Thereafter the as-prepared solution was treated by microwave irradiation of 1 kW for 3 min and consequently a novel N-CD was obtained by the one-pot method. Experimental results indicated that the as-synthesized N-CDs were very soluble in water and exhibited bright blue emission under ultraviolet light. Furthermore, the fluorescence emission was independent of excitation wavelengths. The N-CDs showed an approximately spheric particle with a size of 5-8 nm and an obvious fringe distance of 0.23 nm, close to the (100) crystal lattice distance of graphitic carbon structure. The fluorescence of the obtained N-CDs could be effectively quenched by ferric ions via interacting with functional groups on the surface of N-CDs to form complex compounds. The normalized intensity versus the concentration of ferric ions showed a good linear relationship under the concentration in the range of 5-60 μmol·L-1. The detection limit of ferric ions was estimated to be 1.01 μmol·L-1. These results suggested that the as-synthesized N-CDs could be used as an effective fluorescent sensing platform for ferric ions in water.