International audienceAn innovative and low-cost method is proposed for the detection and discrimination of indole-positive pathogen bacteria. The method allows the non-invasive detection of gaseous indole, released by bacteria, with nanoporous colorimetric sensors. The innovation comes from the use of nanoporous matrices doped with 4-(dimethylamino)-cinnamaldehyde, which act as sponges to trap and concentrate the targeted analyte and turn from transparent to dark green, long before the colonies get visible with naked eyes. With such sensors, it was possible to discriminate E. coli from H. alvei, two indole-positive and negative bacteria after seven hours of incubation

International audienceA new colorimetric and easy-to-use solid sensor for the detection of indole-producing bacteria is described. The sensor is a nanoporous matrix with tailored pores doped with a reactant, DMACA. The sensor turns rapidly from transparent to green-blue when exposed to metabolic indole coming from bacteria cultures, both in liquid and gas phases. An example of the discrimination between indole-positive (Eschericia coli) and indole-negative bacteria (Hafnia alvei), two important contaminants in food industry is given