Schoukroun-Barnes Lauren R, Glaser Ethan P, White Ryan J
Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, Maryland 21250, United States.
Langmuir. 2015 Jun 16;31(23):6563-9. doi: 10.1021/acs.langmuir.5b01418. Epub 2015 Jun 2.
Structure-switching sensors utilize recognition elements that undergo a conformation change upon target binding that is converted into a quantitative signal. Electrochemical, aptamer-based sensors achieve detection of analytes through a conformation change in an electrode-bound, oligonucleotide aptamer by measuring changes in electron transfer efficiencies. The analytical performance of these sensors is related to the magnitude of the conformation change of the aptamer. The goal of the present work is to develop a general method to predictably tune the analytical performance (sensitivity and linear range) of electrochemical, aptamer-based sensors by utilizing a mixture of rationally designed aptamer sequences that are specific for the same target but with different affinities on the same electrode surface. To demonstrate control over sensor performance, we developed heterogeneous sensors for two representative small molecule targets (adenosine triphosphate and tobramycin). We demonstrate that mixtures of modified sequences can be used to tune the affinity, dynamic range, and sensitivity of the resulting sensors predicted by a bi-Langmuir-type isotherm.
结构转换传感器利用识别元件，这些元件在与靶标结合时会发生构象变化，并被转换为定量信号。基于适体的电化学传感器通过测量电极结合的寡核苷酸适体的构象变化所引起的电子转移效率变化来实现对分析物的检测。这些传感器的分析性能与适体构象变化的幅度有关。本工作的目标是开发一种通用方法，通过在同一电极表面使用对同一靶标具有不同亲和力的合理设计的适体序列混合物，可预测地调节基于适体的电化学传感器的分析性能（灵敏度和线性范围）。为了证明对传感器性能的控制，我们针对两个代表性小分子靶标（三磷酸腺苷和妥布霉素）开发了异质传感器。我们证明，修饰序列的混合物可用于调节由双朗缪尔型等温线预测的所得传感器的亲和力、动态范围和灵敏度。
