Real-time capacitance cell sensor

Abstract

We developed capacitance-based cell sensors to monitor cellular activities in real time. Biological cells are enclosed by phospholipids bi-layers, so they may be regarded as dielectric particles and their dielectric properties are dependent on the morphology, membrane potential, etc. As a result, our capacitance sensors could be used to membrane cellular behaviors non-invasively and in real time.We fabricated capacitance sensors where cells were placed between two electrodes, and measured the capacitance as a function of time, to monitor the following cellular activities; (1) all proliferation, (2) all death, (3) endocytosis, and (4) stem cell differentiation. The capacitance increased during proliferation, whereas it decreased during cell death. Furthermore, three types of endocytosis could be distinguished without labeling. In addition, we also calculated the time dependence of capacitance using a dielectric theory and compared with the experimental data. The measured results were explained in terms of cell volume and zeta potential.For high-throughput screening, we fabricated capacitance sensor arrays that consist of 16 sensors and demonstrated the feasibility of chemosensitivity test and antibody screening.