A biosensor is an integrated and autonomous measurement device or system in which a biological element is used for specific stimulus recognition and quantification. This element can be a macro-molecule, an organ or a cell. Here, we use bacteria as the biological element and thus it is a « whole cell biosensor » [1] [2]. A biosensor is composed of a detector element and a reporter element/ The input stimulus will be recognized by the detector, which in turn stimulate the transcription of the reporter gene triggering an output signal.

When using a biosensor, some factors have to be taken in account as they affect the responsiveness of the system. These factors include the choice of host organism, culture medium composition, the growth phase of the harvested bacteria, and the number of bacteria per measurement. It may be possible to improve the performance of biosensors by individually optimizing these factors. [3]

References (Links are provided when available):

1. Bousse, L. (1996). Whole cell biosensors. Sensors and Actuators B: Chemical 34, 270–275.

2. Charrier, T., Jos, M., Affi, M., Jouanneau, S., Gezekel, H., and Thou, G. (2010). Bacterial Bioluminescent Biosensor Characterisation for On-line Monitoring of Heavy Metals Pollutions in Waste Water Treatment Plant Effluents. In Biosensors, P. Andrea, ed. (InTech).

3. Behzadian, F., Barjeste, H., Hosseinkhani, S., and Zarei, A.R. (2011). Construction and Characterization of Escherichia coli Whole-Cell Biosensors for Toluene and Related Compounds. Current Microbiology 62, 690–696.