Nitrogen and sulfur co-doped carbon quantum dots for highly selective and sensitive fluorescent detection of Fe(III) ions and L-cysteine
Nitrogen and sulfur co-doped carbon quantum dots for highly selective and sensitive fluorescent detection of Fe(III) ions and L-cysteine
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用于高选择性和灵敏荧光检测 Fe(III) 离子和 L-半胱氨酸的氮和硫共掺杂碳量子点
DOI：
10.1007/s00604-017-2201-8
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发表时间：
2017-07-01
影响因子：
5.7
通讯作者：
Tong, Changlun
中科院分区：
文献类型：
--
作者：
Wu, Huifang;Jiang, Jiahui;Tong, Changlun
以柠檬酸和半胱氨酸为前驱体，采用水热法合成了高量子产率（69%）、高发光性能的氮硫共掺杂碳量子点（N，S-CQDs）。以HepG 2细胞为靶细胞，采用MTT法检测N，S-CQDs的细胞毒性。在与浓度高达300 μ g中心点mL（-1）的颗粒孵育24小时后，细胞存活率仍> 95%，从而表明N，S-CQD的低细胞毒性和优异的生物相容性。N，S-CQD的发射光谱在280 - 380 nm范围内几乎不受激发波长的影响，并且在415 nm处具有最强的荧光发射。N和S的共掺杂促进了N，S-CQDs与Fe（III）离子之间的电子转移速率和配位相互作用，从而起到荧光猝灭剂的作用。然而，通过添加L-Cys可以恢复荧光。因此，N，S-CQDs作为一个高灵敏度和选择性的“关-开”探针用于Fe（III）或半胱氨酸的测定。检测限为14 nM的Fe（III）和0.54 μ M的半胱氨酸。考察了17种常见金属离子和重金属离子、12种其它猝灭剂和16种氨基酸的干扰，结果表明干扰是可以容忍的。该探针成功地应用于细胞成像的铁（III）在HepG 2细胞通过使用荧光显微镜。
Nitrogen and sulfur co-doped carbon quantum dots (N,S-CQDs) with a high quantum yield (69%) and excellent photoluminescent properties were synthesized via a facile hydrothermal method using citric acid and cysteine as precursors. The cytotoxicity of N,S-CQDs was evaluated through the MTT assays using HepG2 cells as the target. The cell viability is still > 95% after a 24 h incubation with particles in a concentration of up to 300 mu g center dot mL(-1), thereby indicating low cytotoxicity and excellent biocompatibility of N,S-CQDs. The emission spectra of the N,S-CQDs are nearly independent of the excitation wavelengths in the range from 280 to 380 nm and have the strongest fluorescence emission centered at 415 nm. Co-doping with N and S promotes the electron-transfer rate and coordination interaction between N,S-CQDs and Fe(III) ions which acts as a quencher of fluorescence. Fluorescence can be recovered, however, by addition of L-Cys. Hence, the N,S-CQDs act as a highly sensitive and selective "turn-off-on" probe for the determination of Fe(III) or Cys. The limits of detection are 14 nM for Fe(III) and 0.54 mu M for Cys. The interferences by 17 common metal ions and heavy metal ions, 12 other quenchers and 16 amino acids were investigated and found to be tolerable. The probe was successfully applied for cellular imaging of Fe(III) in HepG2 cells by using fluorescence microscopy.