Patent ID: 7968343

Claim:
A method of detecting the presence of a nitro compound in a medium, the method comprising: contacting a medium comprising a nitro compound with a chemical sensor, measuring a change in a response of the chemical sensor, and correlating the change of response to the presence of the nitro compound in the medium; wherein the chemical sensor provides a first response when a medium does not comprise a nitro compound, wherein the chemical sensor provides a second response when a medium comprises a nitro compound, wherein the second response is different from the first response, and where the second response comprises a modification of a physical property of the sensitive material of the chemical sensor when the sensitive material contacts the nitro compound; wherein said chemical sensor comprises: a substrate comprising two faces; wherein at least one of the substrate faces is covered by a thin film; wherein the thin film comprises a sensitive material including at least one polymer comprising a siloxane repeating unit which corresponds to formula (I) below: wherein X and Y, which may be identical or different, represent a single bond or a saturated or unsaturated, linear, branched or cyclic hydrocarbon group comprising from 1 to 30 carbon atoms and, optionally, one or more heteroatoms, and/or one or more chemical functions comprising at least one heteroatom, and/or one or more aromatic or heteroaromatic groups; R 1 represents an aniline group corresponding to formula II below: wherein Q represents a single bond, a —CH 2 —group, or else an —NR 3 —group in which R 3 represents a hydrogen atom or a saturated or unsaturated, linear hydrocarbon group comprising from 1 to 10 carbon atoms; R 4 to R 8 represent, independently of one another, a hydrogen atom, a chemical function comprising at least one heteroatom, or else a saturated or unsaturated, linear, branched or cyclic hydrocarbon group comprising from 1 to 30 carbon atoms and, optionally, one or more heteroatoms, and/or one or more chemical functions comprising at least one heteroatom, and/or one or more aromatic or heteroaromatic groups; wherein, when Q is a single bond or a —CH 2 —group, then at least one of the radicals R 4 to R 8 represents an amino group —NR 9 R 10 in which R 9 and R 10 represent, independently of one another, a hydrogen atom, a chemical function comprising at least one heteroatom, or else a saturated or unsaturated, linear, branched or cyclic hydrocarbon group comprising from 1 to 30 carbon atoms and, optionally, one or more heteroatoms, and/or one or more chemical functions comprising at least one heteroatom, and/or one or more aromatic or heteroaromatic groups; R 2 represents a hydrogen atom or an aniline of formula (II) as defined above; wherein the sensitive material has a physical property which is modified on contact with a chemical species; and wherein the chemical sensor also comprises a means for measuring a change in the physical property of the sensitive material.