Improved Sensitivity for Ratiometric Fluorescence Detection of Ricin Based on "Kinetic Competition" Aptasensing Strategy
Improved Sensitivity for Ratiometric Fluorescence Detection of Ricin Based on "Kinetic Competition" Aptasensing Strategy
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基于“动力学竞争”适体传感策略提高蓖麻毒素比率荧光检测灵敏度
DOI：
10.1016/j.snb.2020.128073
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Du Yan
中科院分区：
文献类型：
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作者：
Qi Lijuan;Han Xu;Du Yan
适体识别机制已经基于由配体调节的适体构象之间的平衡得到了很好的发展，并且可以与用于基于适体的生物传感器的几乎所有种类的读出技术（即，适体传感器）。还研究了一种称为“动力学竞争”的新颖且稳健的适体感测策略，其中阻断剂动力学竞争适体和探针DNA（例如，分子信标）。它改进了开发适体传感器的一般方法，因为它不需要长时间的预平衡，但靶标及其适体的预结合改变了转导信号的动力学竞争。然而，由于其存在背景信号高、在复杂基质中灵敏度和准确度低等缺点，限制了其实际应用。该方法能很好地避免假阳性结果，最大限度地减少背景信号，使检测更加灵敏、准确、可靠和有效。在最佳条件下，该策略有效地提高了灵敏度，降低了背景信号。RTA的检测限（LOD）为0.23 nM，无需任何分离和扩增技术即可实现。回收率为73.8%-111.0%，适用于食品粉末和血清基质的RTA分析。
The aptamer recognition mechanisms have been well developed based on equilibration between aptamer conformations modulated by ligand, and can be compatible with almost all kinds of readout techniques for aptamer-based biosensors (i.e., aptasensors). A novel and robust aptasensing strategy named “kinetic competition” has also been investigated in which the blocker kinetically competes the aptamer and probe DNA (e.g., molecular beacon). It improved general methodology for developing aptasensors because it does not require a lengthy pre-equilibration, but the pre-binding of target and its aptamer alters kinetic competition for transducing signal. However, some disadvantages still limited its practical applications, such as high background signal, low sensitivity and accuracy in complex matrices and so on. Herein, we firstly reported the ratiometric “kinetic competition” aptasensor for ricin A chain (RTA) detection. It can well avoid false positive results and minimize background signals, which achieves more sensitive, accurate, reliable and effective detection. Under optimal conditions, this strategy effectively improved the sensitivity and reduced the background signal. A limit of detection (LOD) of 0.23 nM for RTA could be achieved without any separation and amplification techniques. The recovery data (73.8 %–111.0 %) was also satisfactory for RTA analysis in food powder samples and serum matrix.