A Bipolar Electrochemical Single Entity Bioanalyzer

摘要 该提案是对NIH FOA（PAR-22-126）的回应，该提案“支持探索性研究， 为生物医学研究开发创新技术.”这个R21项目旨在利用高 光学显微镜和非对称双极微电极阵列的灵敏度和分辨率， 一种低成本、高灵敏度的双极电化学阵列平台， 生物目标物种。 许多生物学或临床相关的物种，如某些癌症生物标志物，以非常低的水平存在。 浓度，有时下降到几个副本。这些物种一直难以检测和量化 现有的生物分析方法由于其灵敏度、选择性和响应速度不足而无法实现。到 为了应对这一挑战，我们建议开发一种双极电化学单实体生物分析仪， 将使我们能够分析单个生物物种，例如单一病毒和循环肿瘤外泌体。 该项目的成功建立在PI小组在双极电化学阵列方面的强大专业知识基础上， 微制造传感器和单一实体电分析，并具有三个具体目标。目标1构建了 包含250，000个电极的不对称双极微电极阵列，并表征和优化 进行单一实体分析。目的2将合成和表征Janus Pt/二氧化硅纳米颗粒（NPs）， 使用它们来标记预浓缩到磁性微珠上的分析物种类。目标3将建立一个综合的 通过将双极微电极阵列与光学显微镜相结合， 优化其用于假病毒颗粒和外来体的单一实体生物分析的分析性能。 所提出的分析平台是创新的和强大的单一实体生物分析，由于使用 来放大和读取微小的电化学信号。使用250，000个大数组 用于预富集的双极微电极和磁珠进一步提高了灵敏度，选择性， 和吞吐量。未来的工作将开发一个独立的台式分析仪器，这将是有用的 因为它们通常用于涉及单一实体生物分析的研究和诊断。

Abstract This proposal is in response to NIH FOA (PAR-22-126), which “supports exploratory research leading to the development of innovative technologies for biomedical research...” This R21 project aims to harness the high sensitivity and resolving power of optical microscopy and asymmetric bipolar microelectrode arrays to develop a low-cost, highly sensitive bipolar electrochemical array platform for detecting and counting individual biological target species. Many biologically or clinically relevant species, such as certain cancer biomarkers, present at very low concentrations, sometimes down to a few copies. These species have been difficult to detect and quantify with existing bioanalytical methods due to their insufficient sensitivity, selectivity, and response speed. To address this challenge, we propose to develop a bipolar electrochemical single entity bioanalyzer, which will allow us to analyze individual biological species, such as single viruses and circulating tumor exosomes. The success of this project builds upon the strong expertise of the PI’s group in bipolar electrochemical arrays, microfabricated sensors, and single entity electroanalysis and has three specific aims. Aim 1 builds the asymmetric bipolar microelectrode arrays containing 250,000 electrodes and characterizes and optimizes them for single entity analysis. Aim 2 will synthesize and characterize Janus Pt/silica nanoparticles (NPs) and use them to label analyte species pre-concentrated onto magnetic microbeads. Aim 3 will build an integrated analytical platform by combining the bipolar microelectrode array with optical microscopy, characterize and optimize its analytical performance for single entity bioanalysis of pseudovirus particles and exosomes. The proposed analytical platform is innovative and powerful for single entity bioanalysis due to the use of an optical signal to amplify and read a small electrochemical signal. The use of a large array of 250,000 bipolar microelectrodes and magnetic beads for pre-concentration further enhances the sensitivity, selectivity, and throughput. Future work will develop a standalone benchtop analytical instrument, which will be useful for their general use in research and diagnosis involving single entity bioanalysis.