The use of sensor materials made by the breath figure (BF) method for the detection and identification of toxic and explosive substances in the gas phase is proposed in the work. This method is based on the formation of a porous surface due to condensation of water droplets on the surface of a solution of polystyrene and chloroform at ambient humidity. The fluorophore 1,3,6,8-Tetrakis (trimethylsilylethynyl) pyrene was used as a sensitive element. A melamine sponge was used as a substrate to form the porous structure. The results of LOD determination for nitrobenzene sensors synthesized at different humidity levels are presented: 1) at a humidity of ~ 80%; 2) at a humidity of ~ 40%.