Department of Chemistry and Biochemistry, Florida International University, 11200 SW Eighth Street, Miami, Florida 33199, United States.
Anal Chem. 2020 Apr 7;92(7):5041-5047. doi: 10.1021/acs.analchem.9b05339. Epub 2020 Mar 24.
It is challenging to tune the response of biosensors to a set of ligands, for example, cross-reactivity to a given target family while maintaining high specificity against interferents, due to the lack of suitable bioreceptors. We present a novel approach for controlling the cross-reactivity of biosensors by employing defined mixtures of aptamers that have differing binding properties. As a demonstration, we develop assays for the specific detection of a family of illicit designer drugs, the synthetic cathinones, with customized responses to each target ligand and interferent. We first use a colorimetric dye-displacement assay to show that the binding spectra of dual-aptamer mixtures can be tuned by altering the molar ratio of these bioreceptors. Optimized assays achieve broad detection of synthetic cathinones with minimal response toward interferents and generally demonstrate better sensing performance than assays utilizing either aptamer alone. The generality of this strategy is demonstrated with a dual-aptamer electrochemical sensor. Our approach enables customization of biosensor responsiveness to an extent that has yet to be achieved through any previously reported aptamer engineering techniques such as sequence mutation or truncation. Since multiple aptamers for the designated target family can routinely be identified via high-throughput sequencing, we believe our strategy offers a generally applicable method for generating near-ideal aptamer biosensors for various analytical applications, including medical diagnostics, environmental monitoring, and drug detection.
由于缺乏合适的生物受体，将生物传感器的响应调谐到一组配体（例如，针对给定靶家族的交叉反应性，同时保持对干扰物的高特异性）具有挑战性。我们提出了一种通过使用具有不同结合特性的定义混合物的适体来控制生物传感器的交叉反应性的新方法。作为演示，我们开发了针对一组非法设计药物（即合成苯丙胺类兴奋剂）的特定检测方法，这些药物具有针对每个靶配体和干扰物的定制响应。我们首先使用比色染料置换测定法表明，通过改变这些生物受体的摩尔比，可以调整双适体混合物的结合光谱。优化后的测定法可广泛检测合成苯丙胺类兴奋剂，对干扰物的反应最小，并且通常比单独使用适体的测定法具有更好的传感性能。双适体电化学传感器证明了这种策略的通用性。我们的方法能够在一定程度上定制生物传感器的响应，而这是以前报道的任何适体工程技术（例如序列突变或截断）都无法实现的。由于可以通过高通量测序常规地鉴定出针对指定靶家族的多个适体，因此我们相信我们的策略为针对各种分析应用（包括医疗诊断，环境监测和药物检测）生成近乎理想的适体生物传感器提供了一种普遍适用的方法。
