Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan.
Graduate School of Environmental Studies, Tohoku University, 6-6-11 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan.
ACS Sens. 2020 Mar 27;5(3):740-745. doi: 10.1021/acssensors.9b02061. Epub 2020 Feb 10.
Cell aggregates have attracted much attention owing to their potential applications in tissue engineering and drug screening. To evaluate cellular respiration of individual cell aggregates in these applications, noninvasive and on-chip high-throughput analytical tools are necessary. Electrochemical methods for detecting oxygen concentrations are useful because of their noninvasiveness. However, these conventional methods may be unsuitable for high-throughput detection because it is difficult to prepare many electrodes on a small chip owing to the limitation of area for connecting electrodes. Alternatively, a bipolar electrode (BPE) system offers clear advantages. In this system, electrochemical reactions are induced at both ends of a BPE without complex wiring. In this study, we present a BPE array for detecting the respiratory activity of cell aggregates. Oxygen concentrations near cell aggregates at cathodic poles of BPEs were converted to electrochemiluminescence (ECL) signals of [Ru(bpy)]/tripropylamine at anodic poles of BPEs. To separate ECL chemicals from cell aggregates, we fabricated a closed BPE device containing analytical and reporter chambers. As a proof of concept, 32 BPEs were controlled wirelessly using a pair of driving electrodes, and the respiratory activities of individual MCF-7 cell aggregates as a cancer model were successfully detected by monitoring ECL signals. Compared with conventional electrode arrays for cell analysis, the wiring of the current device was simple because the multiple BPEs functioned with only a single power supply. To the best of our knowledge, this is the first study of on-chip analysis of cellular activity using a BPE system.
细胞聚集体因其在组织工程和药物筛选中的潜在应用而受到广泛关注。为了评估这些应用中单个细胞聚集体的细胞呼吸，需要非侵入性和芯片上高通量的分析工具。检测氧浓度的电化学方法因其非侵入性而具有优势。然而，这些常规方法可能不适合高通量检测，因为由于连接电极的面积有限，在小芯片上制备多个电极是困难的。相比之下，双极电极 (BPE) 系统具有明显的优势。在该系统中，电化学反应在 BPE 的两端诱导，而无需复杂的布线。在这项研究中，我们提出了一种用于检测细胞聚集体呼吸活性的 BPE 阵列。BPE 阴极附近细胞聚集体的氧浓度被转化为 BPE 阳极处[Ru(bpy)]/三丙胺的电化学发光 (ECL) 信号。为了将 ECL 化学物质与细胞聚集体分离，我们制造了一个包含分析和报告腔室的封闭 BPE 装置。作为概念验证，使用一对驱动电极无线控制 32 个 BPE，通过监测 ECL 信号成功检测了单个 MCF-7 细胞聚集体作为癌症模型的呼吸活性。与传统的细胞分析电极阵列相比，由于多个 BPE 仅使用单个电源即可工作，因此当前设备的布线很简单。据我们所知，这是首次使用 BPE 系统进行芯片上细胞活性分析的研究。
