Chemiresistive sensing of organophosphorous compounds using phexafluoroisopropanol phenyl (HFIPP) functionalized graphene

The detection of organophosphorous compounds (OPCs) were performed by using p-hexafluoroisopropanol phenyl (HFIPP) functionalized graphene (GR) via hydrogen bond interactions. For this, HFIPP moiety was covalently functionalized on the surface of GR by diazo reaction. The HFIPP-GR thin film was obtained on pre-fabricated interdigitated electrodes by drop-drying method and the sensing characteristics of HFIPP-GR film towards OMMP (dimethyl methylphosphonate, a model OPC) were investigated. The proposed sensor showed good response towards sensing DMMP vapors at room temperature. In order to see the effect of HFIPP derivatives on sensing DMMP vapors, a comparative study was also conducted with un functionalized graphene. The detection limit of HFIPP-GR sensor against DMMP vapors was found to be 200 ppb. The HFIPP-GR coated sensors showed good selectivity towards sensing DMMP vapors when compared with common organic vapors. (author)