Nitrogen- and Sulfur-Codoped Carbon Dots for Highly Selective and Sensitive Fluorescent Detection of Hg2 Ions and Sulfide in Environmental Water Samples
Nitrogen- and Sulfur-Codoped Carbon Dots for Highly Selective and Sensitive Fluorescent Detection of Hg2 Ions and Sulfide in Environmental Water Samples
复制标题
氮和硫共掺杂碳点用于高选择性和高灵敏度荧光检测环境水样中的 Hg2 离子和硫化物
DOI：
10.1021/acs.jafc.8b07176
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发表时间：
2019
影响因子：
6.1
通讯作者：
Tong Changlun
中科院分区：
文献类型：
--
作者：
Wu Huifang;Tong Changlun
通过简单的水热法合成了荧光量子产率为16.1%、具有良好光致发光性能的氮硫共掺杂碳点（N,S-CD）。通过MTT法评估N,S-CD的细胞毒性，并选择人肝癌HepG2细胞作为靶标。当其浓度达到300 μg/mL时，孵育24小时后细胞活力超过85%，表明N,S-CDs具有较低的细胞毒性和良好的生物相容性。 N,S-CD 的荧光光谱在 295-400 nm 的激发波长范围内依赖于激发，并且发出以 435 nm 为中心的亮蓝色荧光。发现其对 Hg2+ 离子的选择性荧光识别。当向N,S-CDs溶液中添加Hg2+离子时，其亮蓝色荧光被明显猝灭，并且可以通过添加硫化物恢复。因此，我们构建了一种基于 N,S-CDs–Hg2+ 系统的新策略，作为一种高选择性和超灵敏的“关闭-开启”荧光传感，用于检测硫化物。 Hg2+ 离子的检测限 (S/N = 3) 为 83 nM，硫化物的检测限为 11 nM。水样中可能共存的物质（包括 17 种常见金属离子和 11 种阴离子）对 Hg2+ 离子和硫化物检测几乎没有观察到统计学上显着的干扰。该探针成功应用于HepG2细胞中Hg2+离子荧光显微镜的细胞成像。
Nitrogen- and sulfur-codoped carbon dots (N,S-CDs) with a fluorescence quantum yield of 16.1% and good photoluminescent properties were synthesized by a simple hydrothermal method. Cytotoxicity of the N,S-CDs was evaluated by the MTT assay, and human hepatoma HepG2 cells were chosen as the target. The cell viability was more than 85% after 24 h of incubation when its concentration was up to 300 μg/mL, suggesting low cytotoxicity and good biocompatibility of the N,S-CDs. The fluorescence spectra of the N,S-CDs are excitation-dependent in the excitation-wavelength range of 295–400 nm, and it emits bright blue fluorescence centered at 435 nm. Its selective fluorescence recognition for Hg2+ions was found. When Hg2+ions were added to the N,S-CDs solution, its bright blue fluorescence was obviously quenched and could be recovered by the addition of sulfide. Accordingly, a new strategy based on N,S-CDs–Hg2+system as a highly selective and ultrasensitive “turn off–on” fluorescence sensing for the detection of sulfide was fabricated. The limits of detection (S/N = 3) are 83 nM for Hg2+ions and 11 nM for sulfide. Almost no statistically significant interference for Hg2+-ion and sulfide detection was observed among possible coexisting substances in the water samples, including 17 common metal ions and 11 anions. This probe was successfully applied for the cellular imaging of Hg2+ions in HepG2 cells by fluorescence microscopy.