Electrochemical microscopy has been developed in the past decades for imaging biomolecules in single cells; however, electrochemical visualization of an intracellular protein in one cell is difficult. Herein, for the first time, we have developed a model whereby the protein, KDM1/LSD1 antigen, in the nucleus of a single MCF 7 cell could be visualized using wireless bipolar electrochemiluminescence (BPE-ECL). Submicron-sized, single-walled carbon nanotubes were linked with anti-KDM1/LSD1 antibodies and loaded into the cells for the recognition of the corresponding KDM1/LSD1 antigen. With a low electric field of 1000 V/cm, L012, a luminol analog, was oxidized electrochemically at one end of the nanotube that emitted light for the wireless visualization of its location. The significant drop in the applied voltage permitted the observation of apparent ECL emission inside the nucleus of a single cell, supporting the electrochemical imaging of intracellular KDM1/LSD1 antigen at a single-cell level. This work solves a long-standing task in the field of electroanalysis for intracellular wireless visualization, which should advance the development of electrochemistry in single-cell analysis.

电化学显微镜在过去几十年中发展起来，用于对单细胞中的生物分子进行成像。然而，一个细胞中的细胞内蛋白质的电化学可视化是困难的。在此，我们首次开发了一种模型，通过该模型，可以使用无线双极电化学发光 (BPE-ECL) 对单个 MCF 7 细胞核中的蛋白质 KDM1/LSD1 抗原进行可视化。亚微米大小的单壁碳纳米管与抗 KDM1/LSD1 抗体连接并加载到细胞中以识别相应的 KDM1/LSD1 抗原。在 1000 V/cm 的低电场下，L012（一种鲁米诺类似物）在纳米管的一端被电化学氧化，该纳米管发出光以无线显示其位置。施加电压的显着下降允许在单细胞核内观察到明显的 ECL 发射，支持在单细胞水平上对细胞内 KDM1/LSD1 抗原进行电化学成像。这项工作解决了细胞内无线可视化电分析领域的一项长期任务，这将推动单细胞分析中电化学的发展。