A self-calibrating logic system and oxidase-based biosensor using Tb3 -doped carbon dots/DNA conjugates
A self-calibrating logic system and oxidase-based biosensor using Tb3 -doped carbon dots/DNA conjugates
复制标题
使用 Tb3 掺杂碳点/DNA 缀合物的自校准逻辑系统和基于氧化酶的生物传感器
DOI：
10.1016/j.talanta.2018.08.035
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发表时间：
2019
期刊：
影响因子：
6.1
通讯作者：
Zhang Min
中科院分区：
文献类型：
--
作者：
Chen Zi Han;Han Xin Yue;Deng Ling Xue;Lin Zi Yang;Mu Fang Ya;Zhang Shengqiang;Shi Guoyue;Zhang Min
以柠檬酸铵为碳源，Tb3+为掺杂剂，采用水热法制备了Tb3+掺杂碳点(Tb3+@CDS)。引入15bP的富含GT的单链DNA(SsDNA)，通过天线效应敏化Tb3+，产生两个荧光信号(Cds和Tb3+)，形成Tb3+@Cds/ssDNA的偶联物。银离子和半胱氨酸可以可逆地调节Tb~(3+)的比值荧光，其中Tb~(3+)在546 nm处的荧光峰可以切换到“开”或“关”作为信号指示剂，而Cd S在444 nm处的荧光峰不变作为内建参照物。所提出的Tb3+/Cys介导的Tb3+@CDS/ssDNA的可逆荧光变化也被证明可用于设计自校准比率荧光逻辑系统。结合H_2O_2与半胱氨酸的特异反应，将Tb~(3+)@Cds/ss DNA用于H_2O_2的比色荧光检测。更重要的是，该传感策略可以进一步成功地扩展到对过氧化氢产生的氧化酶相关反应的监测，例如GOX生物催化葡萄糖的氧化(检测下限：0.06 μM)，并与商业试剂盒相比在大鼠血清中得到了很好的应用。这项工作揭示了一种新的比率荧光设计，该设计具有成本效益高、制备简单、使用方便等优点，无需化学修饰或荧光标记。
Tb3+-doped carbon dots (Tb3+@CDs) were prepared in a facile hydrothermal method by using ammonium citrate as carbon source and Tb3+as dopant. A 15-bp GT-rich single-strand DNA (ssDNA) was introduced to sensitize Tb3+via the antenna effect for generating two fluorescence signals (CDs and Tb3+), forming a conjugate of Tb3+@CDs/ssDNA. The ratiometric fluorescence of Tb3+@CDs/ssDNA could be reversibly regulated by Ag+and Cys, in which the fluorescence peak at 546 nm of Tb3+could be switched to “On” or “Off” as the signal indicator while the fluorescence peak at 444 nm of CDs remained constant as the build-in reference. The proposed Ag+/Cys-mediated reversible fluorescence changes in Tb3+@CDs/ssDNA was also proven for the design of a self-calibrating ratiometric fluorescence logic system. By integrated with the specific reaction between H2O2and Cys, Tb3+@CDs/ssDNA was applied for ratiometric fluorescence detection of H2O2. More importantly, the sensing strategy could be further successfully extended to the monitoring of H2O2-produced oxidase-related reactions, such as GOx-biocatalyzed oxidation of glucose (the limit of detection: 0.06 μM) and was well applied in rat serum compared to commercial kits. This work unveiled a novel ratiometric fluorescent design, which is cost-effective, simple to prepare and easy-to-use without chemical modification or fluorescence labeling.