A novel aptasensor for the ultra-sensitive detection of adenosine triphosphate via aptamer/quantum dot based resonance energy transfer.
A novel aptasensor for the ultra-sensitive detection of adenosine triphosphate via aptamer/quantum dot based resonance energy transfer.
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DOI：
10.1039/c3an00449j
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发表时间：
2013-07
期刊：
影响因子：
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通讯作者：
Zheng Li;Yijing Wang;Y. Liu;Yongyi Zeng;A. Huang;Niancai Peng;Xiaolong Liu;Jingfeng Liu
中科院分区：
文献类型：
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作者：
Zheng Li;Yijing Wang;Y. Liu;Yongyi Zeng;A. Huang;Niancai Peng;Xiaolong Liu;Jingfeng Liu
我们设计了一种基于核酸适体的共振能量转移生物传感器（aptasensor），用于三磷酸腺苷（ATP）的超灵敏检测。ATP适体3'端修饰Cy 3，5'端连接绿色量子点（525）。在缺乏目标ATP的情况下，ATP适体及其互补序列可以组装成双链体结构，从而缩短量子点与Cy 3之间的距离，产生明显的RET信号。当ATP结合时，ATP适体可以与其互补序列解离，然后增加量子点与Cy 3之间的距离，这将显著降低RET信号。因此，通过检测525 nm和560 nm之间的荧光强度比可以容易地实现ATP检测。结果表明，525/560的发射荧光强度比与ATP浓度的对数成线性关系。该适体传感器的线性范围为0.1 nM ~ 1 μM，检测限为0.01 nM。以三磷酸胸苷（TTP）、三磷酸胞苷（CTP）、三磷酸鸟苷（GTP）和二磷酸腺苷（ADP）为对照，证明该适体传感器对ATP具有良好的选择性。我们在这里描述的方法可以很容易地检测ATP具有良好的选择性，线性和灵敏度低至纳摩尔范围，以及避免光漂白。
We designed a novel aptamer based biosensor (aptasensor) for ultrasensitive detection of adenosine triphosphate (ATP) through resonance energy transfer (RET). The ATP aptamer was modified with Cy3 at the 3' end, and a green quantum dot (525) was attached to the 5' end of its complementary sequence respectively. The ATP aptamer and its complementary sequence could assemble into a duplex structure in the absence of target ATP, and then decrease the distance between the quantum dot and Cy3 which could produce significant RET signal. Upon ATP binding, the ATP aptamer could dissociate with its complementary sequence and then increase the distance between the quantum dot and Cy3 which would significantly decrease the RET signal. Therefore, the ATP detection could be easily achieved through detection of the fluorescence intensity ratio between 525 nm and 560 nm. The results show that the emission fluorescence intensity ratio of 525/560 is linearly related to the logarithmic concentration of ATP. The linear range of this aptasensor is from 0.1 nM to 1 μM, and the detection limit is lower down to 0.01 nM. Excellent selectivity of this aptasensor for ATP has been demonstrated through the detection of thymidine triphosphate (TTP), cytidine triphosphate (CTP), guanosine triphosphate (GTP) and adenosine diphosphate (ADP) respectively as control. The method we described here could easily detect ATP with excellent selectivity, linearity and sensitivity down to the nanomolar range, as well as avoid photobleaching.