Research Of Cell-Substrate Impedance And Extracellular Recording Integrated Biosensor And Its Application In Drug Analysis

Cell electroanalysis, including the cell activity observation and cell growth state determination, plays an important role in cellular research, drug effects, cell engineering, medicine and health, as well as environmental monitoring. This thesis proposing the importance of integrated chip in cell physiological analysis and drug development, provides a High-Content Screening Platforms for Multi-Parameter Studies integrating the electrical cell impedance sensing and extracellular potential recording techniques. The work mainly consists of three parts as follows:In the part of theory and design, the interdigitated electrodes type was chosen to in-depth study of the cell-electrode adhesion impedance model. The optimization was firstly derived from the equivalent circuit, further supplemented by the cell spatial distribution on unit electrode model. Infinite element simulation of electric field of electrode further explored electrode geometry on sensor performance. Based on cell-electrode point-contact model, the transfer function of extracellular recording system was deduced. Based on the electrode size effect and noise source effect on the detected signal, some rules were proposed in microelectrode design. Given the optimization design rules of these two sensing technology, the layout and packaging of integrated chip named "ExCELL" was designed.For the integrated chip system, interdigitated electrodes and micro-electrode integrated chip were fabricated following the processes of metal layer sputtering, electrode pattern photoetching, insulating layer deposition and another photoetching to expose the electrode, finally packaged biocompatibly. Corresponding test station consisted of pogo pins of electric and mechanical property and shielding box, which could ensure the quality of signal condition. Temperature condition system integrated on the station and fluid control automation guaranteed the cell growth and automation experiments.32-channel bio-signal high-gain low-noise amplifier was designed to provide a signal condition of 5.5μVRMS inPut noise and 1000 gain; A multi-channel impedance test system were developed to implement a impedance spectroscopy scan of 100Hz-10KHz bandwidths and long term measurement under single frequency of 10ms time resolution.Using the integrated chip-based system, the process of cell growth of PC 12 cells was monitored and evaluated by analyzing the frequency characteristics and dynamic changes of cell impedance over time. Waveform extraction and clustering method were exploited for the analysis of extracellular potential signal measured from the cardiac cell line HL-1. At last, the simultaneous recording of cell impedance and extracellular potential was realized. The incorporation of these two parameters provided a comprehensive evaluation the acute and chronic toxicity of of adriamycin on cardiac cell line HL-1 in the heart failure model.