School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, P. R. China.
School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, P. R. China.
Sci Rep. 2017 Nov 1;7(1):14866. doi: 10.1038/s41598-017-15054-9.
In the present work, we reported the luminescence of a green-emitting carbon dots (CDs) synthesized via solid state reaction method using diammonium hydrogen citrate and urea as a starting materials. The obtained green-emitting CDs shows strong absorption in the 350-450 nm region and gives intense green emission (λ = 537 nm) with quantum yield as high as 46.4% under 420 nm excitation. The obtained green-emitting CDs also demonstrates high photo-stability, which is evidenced by the fact that its emission intensity almost has no change under irradiation by a 365 nm UV lamp for 2 hours. Moreover, the obtained green-emitting CDs shows high sensitivity and selectivity for the detection of Fe, and their emission intensity response towards Fe ions is highly linear (R = 0.995) over the concentration range from 25 to 300 µM, which could provide an effective platform for detection of Fe. Mostly important, we further demonstrate that such photoluminescent green-emitting CDs exhibits low toxicity and are biocompatible for use with in cellular imaging. Combining with low cytotoxicity, good water solubility and excellent luminescence properties, green-emitting CDs could be used as a biocompatible fluorescent ink in future applications.
在本工作中，我们报道了一种通过固态反应法合成的发绿光碳点（CDs）的发光性能，该方法以二铵柠檬酸盐和尿素为起始原料。所得到的发绿光 CDs 在 350-450nm 区域具有很强的吸收，在 420nm 激发下发出强烈的绿光发射（λ=537nm），量子产率高达 46.4%。所得发绿光 CDs 还表现出很高的光稳定性，这一事实证明，在 365nm 紫外灯下照射 2 小时后，其发射强度几乎没有变化。此外，所得发绿光 CDs 对 Fe 的检测具有高灵敏度和选择性，其对 Fe 离子的发射强度响应在 25-300µM 的浓度范围内具有高度线性（R=0.995），为 Fe 的检测提供了一个有效的平台。最重要的是，我们进一步证明，这种发绿色荧光的 CDs 具有低毒性，可用于细胞成像的生物相容性。结合低细胞毒性、良好的水溶性和优异的发光性能，发绿光 CDs 可用作未来应用中的生物相容性荧光墨水。
