Whole-cell luminescent bioreporter sensors based on immobilized recombinant Escherichia coli are described and evaluated. The sensors were prepared by glutaraldehyde-anchoring of nonspecific anti-E. coli antibodies on aminosylilated gold or silica glass surfaces with subsequent attachment of the probe bacteria. We demonstrate the generality of the concept by attachment of several E. coli strains that express luciferase in response to different physiological stress conditions including heat shock, DNA damage (SOS), fatty acid availability, peroxide and oxidative stress. The sensors can be used either as single- or multiple-use disposable sensing elements or for continuous operation. We show compatibility with optical fiber technology. Storage stability of the sensors exceeded 5 months with no measurable deterioration of the signal. Repeatability on exposure in successive days was < 15%, as was sensor to sensor reproducibility. Sensitivity and detection limits of the immobilized cells were comparable to that of non-immobilized bacteria.
Bibliographical noteFunding Information:
This research was supported by grant number 13139-1-98 of the Infrastructure program of the Ministry of Science and Culture, Israel; 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