Use of siloxane-based polymers or composites in chemical sensor for detecting nitrate compounds

The use of at least one polymer comprising at least one siloxane repeating unit corresponding to the general formula (I) below:

• in which:
• X and Y, which may be identical or different, represent a single bond or a saturated or unsaturated, linear hydrocarbon group containing from 1 to 50 carbon atoms;
• R1 and R2, which may be identical or different, represent a hydrogen atom, a CN group, a group C(Z)3, CH(Z)2 or CH2Z with Z representing a halogen atom;
• an NH2 group, a group NHR3 or NR3R4 with R3 and R4 representing, independently of each other, a halogen atom, a methyl group or a linear or branched, saturated or unsaturated hydrocarbon chain containing from 2 to 20 carbon atoms and possibly one or more heteroatoms and/or one or more chemical functions comprising at least one heteroatom;
• on condition, however, that at least one from among R1 and R2 is not a hydrogen atom;
• or of a composite comprising this polymer and one or more electrically conductive fillers, as sensitive material in a sensor for detecting one or more nitro compounds.