Live Cell-Based Sensor Devices

Living cells maintain life functions by responding quickly and with great sensitivity to changes in the external environment. Consequently, sensors using cells as active elements are thought to be able to perform analyses faster and with more sensitivity than previously possible. Cell-based sensors can be roughly divided into two types. The first uses microorganisms such as Escherichia coli or yeast as active elements (Microbial cells). The second type uses human and animal cells (Mammalian cells). The first type can be cultivated rather easily and has the advantages of being inexpensive and portable. The second type is more complex but has the advantage of potentially being used with human subjects. Most research in this area is concentrated on the first type, microbial sensors, but research on sensors that use mammalian cells has recently become more widespread. We are exploring the modification of mammalian cells using genetic engineering techniques and developing next- generation cell sensors that can visually represent specific reactions. Recently, few researchers, including our group, have successfully produced devices from sensor cells that can process a variety of specimens using MEMS, NEMS, and other nano/micro processing technologies. In this review, we will introduce our research and describe recent trends in this field.