Open AccessInterdigitated aluminium and titanium sensors for assessing epithelial barrier functionality by electric cell-substrate impedance spectroscopy (ECIS)
Author(s) -
Thomas Schmiedinger,
Stefan Partel,
Thomas Lechleitner,
Oliver Eiter,
Daniel Hekl,
Stephan Kaseman,
Peter Lukáš,
Johannes Edlinger,
Judith Lechner,
Thomas Seppi
Publication year - 2020
Publication title -
biomedical microdevices
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.629
H-Index - 88
eISSN - 1572-8781
pISSN - 1387-2176
DOI - 10.1007/s10544-020-00486-4
Subject(s) - materials science , aluminium , ohmic contact , titanium , dielectric spectroscopy , substrate (aquarium) , electrode , electrical impedance , electrolyte , biomedical engineering , analytical chemistry (journal) , nanotechnology , optoelectronics , composite material , chemistry , metallurgy , electrical engineering , medicine , oceanography , engineering , layer (electronics) , electrochemistry , chromatography , geology
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.