Department of Pharmaceutical Science, Leslie Dan Faculty of Pharmacy, University of Toronto , Toronto, Ontario M5S 3M2 Canada.
Département de Chimie, Université de Montréal , Montréal, Québec H3T 1J4 Canada.
Anal Chem. 2017 Sep 19;89(18):9751-9757. doi: 10.1021/acs.analchem.7b01595. Epub 2017 Sep 5.
The availability of rapid approaches for quantitative detection of biomarkers would drastically impact global health by enabling decentralized disease diagnosis anywhere that patient care is administered. A promising new approach, the electrochemical steric hindrance hybridization assay (eSHHA) has been introduced for quantitative detection of large proteins (e.g., antibodies) with a low nanomolar detection limit within 10 min. Here, we report the use of a nanostructured microelectrode (NME) platform for eSHHA that improves the performance of this approach by increasing the efficiency and kinetics of DNA hybridization. We demonstrated that eSHHA on nanostructured microelectrodes leverages three effects: (1) steric hindrance effects at the nanoscale, (2) a size-dependent hybridization rate of DNA complexes, and (3) electrode morphology-dependent blocking effects. As a proof of concept, we showed that the sensitivity of eSHHA toward a model antibody is enhanced using NMEs as scaffolds for this reaction. We improved the detection limit of eSHHA, taking advantage of nanostructured surfaces to allow the use of longer capture strands for detection of proteins. Finally, we concluded that using the eSHHA approach in conjunction with nanostructured microelectrodes is an advantageous alternative to conventional macroelectrodes as the sensitivity and detection limits are enhanced.
快速定量检测生物标志物的方法的可用性将通过在任何提供患者护理的地方实现疾病的分散诊断，从而对全球健康产生重大影响。电化学空间位阻杂交分析（eSHHA）作为一种新的有前途的方法，已被引入用于定量检测大蛋白（例如抗体），检测限可达低纳摩尔，时间在 10 分钟内。在这里，我们报告了使用纳米结构微电极（NME）平台进行 eSHHA，该平台通过提高 DNA 杂交的效率和动力学来提高该方法的性能。我们证明了在纳米结构微电极上进行 eSHHA 利用了三个效应：（1）纳米尺度上的空间位阻效应，（2）DNA 复合物的尺寸依赖性杂交速率，和（3）电极形态依赖性阻塞效应。作为概念验证，我们表明，通过使用 NME 作为这种反应的支架，可以增强 eSHHA 对模型抗体的敏感性。我们利用纳米结构表面提高了 eSHHA 的检测限，从而可以使用更长的捕获链来检测蛋白质。最后，我们得出结论，与传统的宏观电极相比，将 eSHHA 方法与纳米结构微电极结合使用是一种有利的替代方法，因为灵敏度和检测限得到了提高。
