School of Engineering and Materials Science , Queen Mary University of London , Mile End Road , London E1 4NS , U.K.
Institute of Medical Engineering, School of Basic Medical Sciences , Xi'an Jiaotong University Health Science Center , Xi'an , 710061 , China.
Anal Chem. 2019 May 7;91(9):5896-5903. doi: 10.1021/acs.analchem.9b00304. Epub 2019 Apr 24.
The surface charge of cells affects cell signaling, cell metabolic processes, adherence to surfaces, and cell proliferation. Our understanding of the role of membrane charges is limited due to the inability to observe changes without interfering, chemically or physically, with the cell or its membrane. Here, we report that a photoelectrochemical imaging system (PEIS) based on label-free ac-photocurrent measurements at indium tin oxide (ITO) coated glass substrates can be used to map the basal surface charge of single live cells under physiological conditions. Cells were cultured on the ITO substrate. Photocurrent images were generated by scanning a focused, modulated laser beam across the back of the ITO coated glass substrate under an applied bias voltage. The photocurrent was shown to be sensitive to the negative surface charge of the substrate facing, basal side of a single living cell-an area not accessible to other electrochemical or electrophysiological imaging techniques. The PEIS was used to monitor the lysis of mesenchymal stem cells.
细胞的表面电荷会影响细胞信号转导、细胞代谢过程、细胞与表面的黏附以及细胞增殖。由于无法在不与细胞或其膜发生化学或物理干扰的情况下观察到变化，我们对膜电荷作用的理解受到限制。在这里，我们报告了一种基于无标记 ac 光电流测量的光电化学成像系统（PEIS），该系统可用于在生理条件下对单个活细胞的基底表面电荷进行成像。细胞在 ITO 基底上培养。在施加偏置电压的情况下，通过在 ITO 涂覆的玻璃基底的背面扫描聚焦调制激光束来生成光电流图像。结果表明，光电流对单个活细胞基底侧（其他电化学或电生理成像技术无法到达的区域）面对的负基底表面电荷敏感。PEIS 用于监测间充质干细胞的裂解。
