以邻苯二胺和无水氯化锰为原料，水热法合成发射橘红色荧光的锰掺杂碳点（Mn-CDs），对其进行形貌表征、官能团和表面分析以及光学性能表征。结果显示，Mn-CDs呈现为尺寸范围在3.0~8.0 nm的球形形状，且粒径均匀，平均粒径为6.75 nm；该碳点表面含有丰富的—COOH和—NH₂等水溶性官能团，使得该碳点在水中有很好的分散性。在最佳激发波长为440 nm的照射下，最佳发射波长为599 nm，且荧光很稳定。在pH=7.4的磷酸盐溶液中测定不同离子对Mn-CDs的荧光影响发现，只有Cu²⁺能够对Mn-CDs荧光进行明显猝灭，而精氨酸（Arg）能够对淬灭荧光进行明显恢复。以上荧光猝灭与恢复的强度与Cu²⁺及Arg的浓度存在较好的线性关系，表明合成的Mn-CDs可以作为检测Cu²⁺和Arg的分析平台，Cu²⁺和Arg的最低检出限分别为0.234、0.650 μmol/L。

Manganese-doped carbon dots (Mn-CDs) that emitting orange fluorescence are synthesized by a one-step hydrothermal method with o-phenylenediamine and anhydrous manganese chloride as precursors,and their morphology,functional groups,surface and optical properties are characterized.The results show that Mn-CDs presents a spherical shape with an average particle size of 6.75 nm in the range of 3.0-8.0 nm and a narrow size-distribution.In addition,the surface of Mn-CDs is rich in water-soluble functional groups such as —COOH and —NH₂,making them have a good dispersion in water.Under the irradiation with the optimized excitation wavelength of 440 nm,the best emission wavelength of Mn-CDs is 599 nm,and the fluorescence is very stable.Effects of different ions on the fluorescence of Mn-CDs are measured in phosphate solution with a pH of 7.4,and it is found that only Cu²⁺ can significantly quench the fluorescence of Mn-CDs,while arginine can significantly recover the quenched fluorescence.There are good linear relationships between the quenching and the concentration of Cu²⁺,and between the recovering and the concentration of arginine,indicating that the synthesized Mn-CDs can be used as a platform for detecting Cu²⁺ and arginine,with the lowest detection limits of 0.234 μmol·L^-1 and 0.65 μmol·L^-1,respectively.

陈修阳(1979-),男,硕士,高级工程师,从事粉体微纳米材料的基础与应用研究,xychen2598@126.com