Cao Yuping, Zhang Jin, Yang Jilu, Qin Wenwu
Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Special Function Materials and Structure Design (MOE), College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 P. R. China
Academy of Plateau Science and Sustainability, People's Government Of Qinghai Province & Beijing Normal University Xining 810016 China.
RSC Adv. 2023 May 16;13(22):15006-15014. doi: 10.1039/d3ra01540h. eCollection 2023 May 15.
Covalent organic frameworks (COFs) for detecting biological macromolecules in water or biological environments are generally challenging. In this work, a composite material IEP-MnO is obtained by combining manganese dioxide (MnO) nanocrystals and a fluorescent COF (IEP), which is synthesized by using 2,4,6-tris(4-aminophenyl)--triazine and 2,5-dimethoxyterephthalaldehyde. By the addition of biothiols, such as glutathione, cysteine or homocysteine with different sizes, the fluorescence emission spectra of IEP-MnO changed ("turn-on" or "turn-off") different mechanisms. The fluorescence emission of IEP-MnO increased in the presence of GSH by the elimination of the FRET (Förster resonance energy transfer) effect between MnO and IEP. Surprisingly, due to the formation of a hydrogen bond between Cys/Hcy and IEP, the fluorescence quenching for IEP-MnO + Cys/Hcy may be explained the photoelectron transfer (PET) process, which endows IEP-MnO with specificity in distinguishing the detection of GSH and Cys/Hcy compared to other MnO complex materials. Therefore, IEP-MnO was used to detect GSH and Cys in human whole blood and serum, respectively. The limit of detection for GSH in whole blood and Cys in human serum was calculated to be 25.58 μM and 4.43 μM, which indicates that IEP-MnO can be used to investigate some diseases related to GSH and Cys concentration. Moreover, the research expands the application of covalent organic frameworks in the fluorescence sensing field.
用于检测水或生物环境中生物大分子的共价有机框架（COF）通常具有挑战性。在这项工作中，通过将二氧化锰（MnO）纳米晶体与荧光COF（IEP）结合获得了一种复合材料IEP-MnO，IEP是使用2,4,6-三（4-氨基苯基）-三嗪和2,5-二甲氧基对苯二甲醛合成的。通过添加不同大小的生物硫醇，如谷胱甘肽、半胱氨酸或同型半胱氨酸，IEP-MnO的荧光发射光谱会因不同机制而发生变化（“开启”或“关闭”）。在谷胱甘肽存在下，由于MnO与IEP之间的荧光共振能量转移（FRET）效应被消除，IEP-MnO的荧光发射增强。令人惊讶的是，由于半胱氨酸/同型半胱氨酸与IEP之间形成了氢键，IEP-MnO + 半胱氨酸/同型半胱氨酸的荧光猝灭可能是由光电子转移（PET）过程引起的，这使得IEP-MnO在区分谷胱甘肽和半胱氨酸/同型半胱氨酸的检测方面相对于其他MnO复合材料具有特异性。因此，IEP-MnO分别用于检测人全血和血清中的谷胱甘肽和半胱氨酸。计算得出全血中谷胱甘肽和人血清中半胱氨酸的检测限分别为25.58 μM和4.43 μM，这表明IEP-MnO可用于研究一些与谷胱甘肽和半胱氨酸浓度相关的疾病。此外，该研究扩展了共价有机框架在荧光传感领域的应用。
