CELLTOX · Integration of living cells with organic transistors for the rapid detection of toxins and enteric pathogens

The epithelium plays a significant role in resistance to infection in mammals, and is made up of a single layer of elongated, column-shaped cells that line the stomach and colon. This single layer of epithelial cells restricts the entry of toxins and pathogens, while selectively absorbing nutrients that sustain the body. Pathogens have devised multiple mechanisms to destroy the integrity of the intestinal epithelial barrier, compromising the normal absorption of water in the intestine and thereby causing diarrheal disease. The World Health Organization estimates that in 2005 alone 1.8 million people died from diarrheal diseases. CELLTOX is a novel type of biosensor for the detection of enteric pathogens and toxins, based on the principle of using live epithelial cells grown on an organic electrochemical transistor (OECT), which provides a very sensitive and convenient means of measuring ionic transport. When the epithelial cells form a monolayer, the integrity of the cell monolayer prohibits ion transport keeping the transistor in the ON state. Assault of the cells by an enteric pathogen or toxin will lead to a disruption of the cell monolayer and enable ion migration into the polymer, switching the transistor OFF. This novel “canary in a coal mine” platform will constitute a broad first-line diagnostic for gastrointestinal disease, with applications for food and water safety. It will lead to sensors that are fast, portable, inexpensive and label-free. Future use of different cell lines (eg. bronchial, dermal, etc.) with this platform will lead to a host of sensors for applications in medical diagnostics, agriculture, and environmental protection. This multidisciplinary project encompasses the disciplines of organic electronics, cell biology and microbiology, and will contribute to the successful and lasting reintegration of the applicant back to Europe.