Detection of I- in Water by the Hg2+@CDs Fluorescent Sensor
YE Jia-wen1, CHANG Jing-jing1*, GENG Yi-jia2, CUI Yuan1*, XU Shu-ping2, XU Wei-qing2, CHEN Qi-dan3
1. School of Chemical and Environmental Engineering, Changchun University of Science and Technology, Changchun 130022, China
2. State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130012, China
3. School of Chemical Industry and New Energy Materials, Zhuhai College, Jilin University, Zhuhai 519041, China
Abstract：In the human body, iodine is the key raw material for thyroid hormone. Moreover, thyroid hormone had a critical role in human growth and development and regulated metabolism, so iodine was played a vital role in the normal operation of the human body. The iodine was mainly in the form of iodinated amino acids presented in the thyroid gland. Furthermore, many methods were used to detect I- with high precision and accuracy. However, most of the approaches lie in complicated operations and high detection cost. Therefore, it is of great significance to develop a method for detecting I- with low cost, fast, accuracy and simple operation. In this study, a simple and convenient fluorescence “Off-On” detection method was used for I- testing in solution. The carbon nanodots (CDs) were synthesized by a simple hydrothermal method, which citric acid and ethane diamine were used as the carbon source and the nitrogen source. The optical properties of the CDs were characterized by a fluorescence spectrometer and an ultraviolet-visible spectrometer, which emitted bright blue light at an excitation wavelength of 350 nm. Additionally, the groups on the surface of the CDs were characterized by the Fourier-infrared spectroscopy and high resolution ultraviolet photoelectron spectroscopy. The fluorescence of the prepared CDs can be pre-quenched by Hg2+. And the fluorescence quenching may be due to the non-radiative electron-transfer from the excited states to the d orbital of Hg2+. Another possible explanation is attributed to the Hg2+ ions combine with a large amount of nitrogen on the surface of the CDs to form a non-fluorescent complex, which leads to fluorescence quenching of CDs. The optimal concentration condition of Hg2+ was selected by analyzing the fluorescence spectrum of CDs solution with different concentration Hg2+. Once they meet I- in the solution, Hg2+ on the surface of the CDs will be released due to the strong interaction between Hg2+ and I-, and the fluorescence of CDs can be restored. Thus, I- in the solution can be detectable by this fluorescent “Off-On” method, and the detection range is 5.0～75 μmol·L-1 with the detection limit of 0.25 μmol·L-1. Finally, the selectivity and anti-interference ability of Hg2+@CDs fluorescence sensing system were analyzed by fluorescence spectrum. And the results showed that the fluorescence sensing system had high selectivity to I- and good ion anti-interference performance.
叶嘉文，常晶晶，耿乙迦，崔 媛，徐抒平，徐蔚青，陈奇丹. Hg2+@CDs的荧光传感体系检测水质中的I-[J]. 光谱学与光谱分析, 2020, 40(11): 3489-3493.
YE Jia-wen, CHANG Jing-jing, GENG Yi-jia, CUI Yuan, XU Shu-ping, XU Wei-qing, CHEN Qi-dan. Detection of I- in Water by the Hg2+@CDs Fluorescent Sensor. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(11): 3489-3493.
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