Figure 1.

Whole-cell biosensor for iron monitoring. Iron is internalized within cells through mechanisms mediated by the siderophores uptake system, heme uptake system, or Feo system. Once inside, iron is sensed by transcription factors, including transcription activators (one-component or two-component regulators) and repressors, which regulate the expression of the reporter gene. Based on the applied reporter, a fluorescent, bioluminescent, colourimetric, or bioelectric output signal is obtained, allowing for the measurement of bioavailable iron. Created with graphical elements available on https://app.biorender.com/ (accessed on 8 April 2024).