College of Chemistry and Biologic Engineering, Changsha University of Science and Technology, Changsha 410004, People's Republic of China.
College of Chemistry and Biologic Engineering, Changsha University of Science and Technology, Changsha 410004, People's Republic of China.
Biosens Bioelectron. 2018 Feb 15;100:79-84. doi: 10.1016/j.bios.2017.08.031. Epub 2017 Aug 30.
As a new member of the carbon quantum-dot family, fluorescent nitrogen-rich quantum dots (NRQDs) were prepared by a mixed solvothermal method using 2-azidoimidazole and aqueous ammonia as reactants. These NRQDs are rich in nitrogen up to 40.2%, which are endowed with high fluorescence quantum yield, good photostability, water-solubility and favourable biocompatibility. We further explored the use of NRQDs combined with Cu as a nanoprobe for sensing fluorescently of cysteine (Cys) in complex biological samples. In this sensing system, the fluorescence is significantly quenched via energy transfer from NRQDs to Cu for the coordination of amino-containing groups with Cu. The strong affinity between Cu and Cys leads to the formation of Cu-Cys complexes and cause the detachment of Cu from the surface of NRQDs, thus the fluorescence of NRQDs recover. This nanoprobe allows analysis of Cys by modulating the switch of the fluorescence of NRQDs with a detection limit of 5.3nM. As expected, the proposed NRQDs-Cucomplex-based nanoprobes were successfully applied for the determination of Cys in human serum and plasma samples with recoveries ranging from 97.2% to 105.7%. The probe ensemble was also successfully applied to imaging of Cys in living cells with satisfactory results, which shows strong potential for clinical diagnosis.
作为碳量子点家族的新成员，通过混合溶剂热法以 2-叠氮咪唑和氨水为反应物制备了富氮荧光量子点（NRQDs）。这些 NRQDs 富含高达 40.2%的氮，具有高荧光量子产率、良好的光稳定性、水溶性和良好的生物相容性。我们进一步探索了将 NRQDs 与 Cu 结合作为纳米探针用于检测复杂生物样品中半胱氨酸（Cys）的荧光。在这个传感系统中，通过 NRQDs 与 Cu 之间的能量转移，荧光显著猝灭，因为含氨基的基团与 Cu 配位。Cu 与 Cys 之间的强亲和力导致 Cu-Cys 配合物的形成，并导致 Cu 从 NRQDs 表面脱离，从而恢复 NRQDs 的荧光。该纳米探针通过调节 NRQDs 荧光的开关来分析 Cys，检测限为 5.3nM。不出所料，所提出的基于 NRQDs-Cu 配合物的纳米探针成功地用于测定人血清和血浆样品中的 Cys，回收率在 97.2%至 105.7%之间。该探针集还成功地用于活细胞中 Cys 的成像，取得了令人满意的结果，这表明其在临床诊断方面具有很大的潜力。
