Development of an electrochemical insulin sensor based on the insulin-linked polymorphic region
Development of an electrochemical insulin sensor based on the insulin-linked polymorphic region
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DOI：
10.1016/j.bios.2012.10.046
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发表时间：
2013-04-15
影响因子：
12.6
通讯作者：
Lai, Rebecca Y.
中科院分区：
文献类型：
--
作者：
Gerasimov, Jennifer Y.;Schaefer, Cody S.;Lai, Rebecca Y.
在这里，我们报告的设计和制作的电化学适配体为基础的（E-AB）传感器检测胰岛素。本研究中使用的适体是胰岛素连接多态性区域（ILPR）序列，这是一种富含G的序列，在胰岛素存在下，该序列可能经历配体诱导的折叠以形成G-四链体。然而，我们的圆二色性数据表明，ILPR序列，即使在没有目标，主要是在一个G-四链体样的形式。然而，胰岛素结合已显示进一步诱导G-四链体的形成。为了评估ILPR序列作为生物传感元件的潜力，我们构建了两个E-AB胰岛素传感器，除了亚甲蓝（MB）氧化还原标记的位置之外，它们在所有方面都是相同的。我们发现，与内部MB修饰的探针（在IT）制造的传感器相比，使用终端MB修饰的探针（在1）制造的传感器显示增强的传感行为。用In-IT传感器观察到的改善可归因于在胰岛素结合时更有效地阻碍电子转移。总体而言，两种传感器表现良好，分别为In-IT和In 1传感器提供10 nM和50 nM的检测限。(C)2012 Elsevier B. V.保留所有权利。
Here we report the design and fabrication of an electrochemical aptamer-based (E-AB) sensor for detection of insulin. The aptamer used in this study is the insulin-linked polymorphic region (ILPR) sequence, a G-rich sequence that presumably undergoes ligand-induced folding to form a G-quadruplex in presence of insulin. Our circular dichroism data, however, suggests that the ILPR sequence, even in absence of the target, is predominantly in a G-quadruplex-like form. Insulin binding, however, has shown to further induce the formation of the G-quadruplex. To evaluate the potential of the ILPR sequence as a biosensing element, we constructed two E-AB insulin sensors that are identical in all aspects but the location of the methylene blue (MB) redox label. We find that the sensor fabricated with internal MB-modified probes (In-IT) shows enhanced sensing behavior when compared to one fabricated using terminal-MB modified probes (In1). The improvements observed with the In-IT sensor could be attributed to the more effective obstruction of electron transfer upon insulin binding. Overall, both sensors perform well, affording a detection limit of 10 nM and 50 nM for the In-IT and In1 sensors, respectively. (C) 2012 Elsevier B.V. All rights reserved.