Artificial cell cultures have become increasingly important in biotechnology, pharma, and food industries and are used to produce proteins, antibodies, enzymes, engineered tissue, artificial organs, and food products. During cell culture, it is critical to control glucose concentration in cell culture media, as this is a determining factor for quality control and maintaining optimal cell culture growth conditions. Since glucose is consumed by living cells during their growth and proliferation, its concentration should be monitored during the process. This requires continuous monitoring devices, which can be integrated into cell culture incubators. Although a variety of solutions for continuous glucose monitoring exist, there is a demand for more robust, compact, sensor devices which are stable over a long period of time.
We are developing a compact optical sensor for glucose monitoring in cell culture media. The sensor employs innovative sensing technology which was invented at École Polytechnique Fédérale de Lausanne (EPFL), combined with optical readout developed at CSEM. This technology uses single-walled carbon nanotubes (SWCNTs) as optical transducers. A bio-engineered glucose-sensitive enzyme, glucose oxidase (GOx) is site-specifically anchored onto the surface of the SWCNT using aromatic cross-linker molecules, forming a stable conjugate. The conjugate material is applied as a sensor coating in the optical device. This SWCNT-based sensor technology has the potential to extend the life cycle of enzymatic sensors for long-term continuous monitoring of glucose.