A class of sensing elements based on the encapsulation of genetically engineered bioluminescent Escherichia coli (E. coli) reporter strains in sol-gel derived silicates is described. We demonstrate the concept by the immobilization of these bacterial cells in thick silicate films. Heat shock, oxidative stress, fatty acids, peroxides, and genotoxicity reporting bacteria were incorporated in the sol-gel silicates and their luminescence response was compared to that of the non-immobilized culture. All the immobilized bacteria maintained viability and luminescence activity for several months. The bacteria-silicate hybrids can be used either as disposable sensors or in multiple use sensing test-kits, and they can be also integrated in early warning devices operated in continuous flow conditions.
Bibliographical noteFunding Information:
This research was supported by the Infrastructure Program of the Ministry of Science, Culture, and Sport, Israel, and by a Franco-Israel research grant; Instrumentation was partly funded by the Israel Science Foundation, founded by the Israel Academy of Sciences. We gratefully acknowledge strains provided by T.K. Van Dyk and R.A. LaRossa, the DuPont Company, USA.
- E. coli
- Genotoxicity testing
- Toxicity testing