Prof. Moongyu Jang
School of Nano Convergence Technology, Hallym University, Chuncheon 24252, South KoreaSpeech Title: Real time capacitance variation monitoring due to cell-drug reactions using single and multi-well array ECIS impedance biosensor in NIH/3T3 cells
Abstract: Electric Cell-substrate Impedance Sensing (ECIS)-based impedance biosensors have been extensively studied across various fields, including oncology, microbiology, and immunology. This study aimed to investigate the capacitance dependence of NIH/3T3 cells based on their spatial positioning—either on the electrodes or between the electrodes—within an impedance biosensor. To evaluate this, we fabricated electrode patterns with two different gap distances: a wide-gap pattern (3.7 mm) and a narrow-gap pattern (0.3 mm). The capacitance contributions from cells located on and between the electrodes were analyzed using these patterns.
Detailed analysis revealed that cells positioned directly on the electrodes contributed less than 20% to the total measured capacitance, whereas the majority of the capacitance originated from cells located between the electrodes. This result emphasizes the critical role of the inter-electrode region and suggests that minimizing the electrode area while maximizing the gap spacing is essential for accurately measuring cell capacitance.
Additionally, to address challenges related to scalability, reproducibility, and analytical limitations in conventional impedance biosensors, we developed a multi-well array ECIS-based impedance biosensor by integrating array technology with standard ECIS methods. This biosensor enables simultaneous, real-time monitoring of cell growth and drug responses across multiple wells. The consistent responses across wells demonstrate the system’s reliability and robustness.
Furthermore, by applying varying drug concentrations in individual wells, we created an independent 2×2 impedance biosensing environment for drug screening. Using this setup, we successfully performed IC50 (half-maximal inhibitory concentration) analysis to assess drug efficacy. The system revealed that capacitance changes sensitively reflected dose-dependent drug effects, validating the biosensor's capability for pharmacological studies.
This research presents a novel multi-well array impedance biosensor that combines the advantages of ECIS technology and microarray integration. It offers enhanced throughput, reproducibility, and analytical precision, highlighting its potential as a next-generation platform for drug discovery and biomedical applications.
Keywords: ECIS, Semiconductor, Array, Capacitance, IC50, Biosensor