Plants have amazing and significant sensing capabilities. We proposed the use of plants themselves as sensing devices to detect different compounds or environmental conditions. Using plant promoters that are activated in the presence of high concentrations of CO2, selected by the NavarraBG team, we have produced Arabidopsis plants capable of acting as biosensors against this metabolite. The results obtained open new possibilities for the use of plants as biosensors for other soil pollutant molecules or specific conditions. In this project, we also use Synthetic Biology to design new gene reporter constructs that facilitate the visualization of the response of the biosensor plant without the need for complex equipment. In addition, we explored the use of sequences fused to the reporter protein to control its degradation once the stimulus is terminated.