Innovative colorimetric sensors for the detection of nitrogen trichloride at ppb level in swimming pools

The development of new chemical sensors for the direct detection of nitrogen trichloride, NCl3, a toxic pollutant present in the atmosphere of indoor swimming pools, is described. These innovative chemical and colorimetric sensors are based on the use of nanoporous matrices doped with probe-molecules, which act as sponges to trap the targeted pollutant and turn from transparent to pink-violet. These sensors can detect NCl3 at ppb level within 15 min in humid atmosphere. Due to the fast change of color, visible with naked eyes, these sensors can be used to detect peaks of pollution and to monitor the air quality of indoor pools in public or private area. The technology was transferred from Francis Perrin Laboratory (LFP) to ETHERA, a CEA-CNRS4 spin-off, which optimizes both the sensor synthesis for mass production and the quality control procedures needed for marketing. Validation of analytical procedures and sensor response in real environment is accomplished via a campaign of NCl3 measurements in a Parisian swimming pool.