A specific nanoprobe for cysteine based on nitrogen-rich fluorescent quantum dots combined with Cu2+
A specific nanoprobe for cysteine based on nitrogen-rich fluorescent quantum dots combined with Cu2+
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基于富氮荧光量子点结合Cu2的半胱氨酸特异性纳米探针
DOI：
10.1016/j.bios.2017.08.031
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发表时间：
2018-02-15
影响因子：
12.6
通讯作者：
Chen, Xuejiao
中科院分区：
文献类型：
--
作者：
Gu, Tingting;Zou, Wu;Chen, Xuejiao
以2-叠氮咪唑和氨水为反应物，采用混合溶剂热法制备了荧光富氮量子点（NRQDs）。这些NRQDs富含氮高达40.2%，具有高的荧光量子产率，良好的光稳定性，水溶性和良好的生物相容性。我们进一步探索了使用NRQD与Cu 2+结合作为纳米探针用于感测复杂生物样品中半胱氨酸（Cys）的荧光。在该传感系统中，荧光显着淬灭通过能量转移从NRQDs到Cu 2+的含氨基基团与Cu 2+的配位。Cu ~（2+）与Cys之间的强亲和力导致Cu ~（2+）-Cys形成复合物，并使Cu ~（2+）从NRQDs表面脱离，从而使NRQDs的荧光恢复。这种纳米探针允许通过调节NRQD的荧光开关来分析Cys，检测限为5.3 nM。正如预期的那样，所提出的基于NRQDs-Cu（2+）络合物的纳米探针成功地应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。该探针组合也成功地应用于活细胞中Cys的成像，结果令人满意，显示出很强的临床诊断潜力。
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 Cu2+ 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 Cu2+ for the coordination of amino-containing groups with Cu2+. The strong affinity between Cu2+ and Cys leads to the formation of Cu2+-Cys complexes and cause the detachment of Cu2+ 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 5.3 nM. As expected, the proposed NRQDs-Cu(2+)complex-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.