Electric cell-substrate impedance spectroscopy (ECIS) enables non-invasive and continuous read-out of electrical parameters of living tissue. The aim of the current study was to investigate the performance of interdigitated sensors with 50 μm electrode width and 50 μm inter-electrode distance made of gold, aluminium, and titanium for monitoring the barrier properties of epithelial cells in tissue culture. At first, the measurement performance of the photolithographic fabricated sensors was characterized by defined reference electrolytes. The sensors were used to monitor the electrical properties of two adherent epithelial barrier tissue models: renal proximal tubular LLC-PK1 cells, representing a normal functional transporting epithelium, and human cervical cancer-derived HeLa cells, forming non-transporting cancerous epithelial tissue. Then, the impedance spectra obtained were analysed by numerically fitting the parameters of the two different models to the measured impedance spectrum. Aluminium sensors proved to be as sensitive and consistent in repeated online-recordings for continuous cell growth and differentiation monitoring as sensors made of gold, the standard electrode material. Titanium electrodes exhibited an elevated intrinsic ohmic resistance in comparison to gold reflecting its lower electric conductivity. Analysis of impedance spectra through applying models and numerical data fitting enabled the detailed investigation of the development and properties of a functional transporting epithelial tissue using either gold or aluminium sensors. The result of the data obtained, supports the consideration of aluminium and titanium sensor materials as potential alternatives to gold sensors for advanced application of ECIS spectroscopy.

中文翻译：

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叉指式铝和钛传感器，用于通过电池-基底阻抗谱（ECIS）评估上皮屏障功能。

电池-基板阻抗谱（ECIS）能够无创且连续地读取活组织的电参数。本研究的目的是研究由金，铝和钛制成的，电极宽度为50μm，电极间距离为50μm的叉指式传感器的性能，以监测组织培养中上皮细胞的屏障特性。首先，通过定义的参比电解质来表征光刻制造的传感器的测量性能。传感器用于监测两种粘附的上皮屏障组织模型的电学性质：代表正常功能性上皮的肾近端肾小管LLC-PK1细胞和人类宫颈癌衍生的HeLa细胞，形成非运输性癌上皮组织。然后，通过将两个不同模型的参数数值拟合到测量的阻抗谱来分析获得的阻抗谱。在连续的在线记录中，铝传感器与连续的在线生长和分化监测一样灵敏且一致，与标准电极材料金制成的传感器一样敏感。与金相比，钛电极具有更高的固有欧姆电阻，这反映了其较低的电导率。通过应用模型和数值数据拟合分析阻抗谱，可以使用金或铝传感器对功能性上皮组织的发育和特性进行详细研究。获得数据的结果，