Study of Poly(3-hexyltiophene) Polymer Sensing Properties in Nerve Agent Simulant (DMMP) Detection

Abstract

Abstract:In the present work we report the use of regioregular poly(3-hexyltiophene) polymer (RR-P3HT) as a resistive sensor for the detection of chemical nerve agent simulant, dimethyl methylphosphonate (DMMP). The electrical response to DMMP vapour of RR-P3HT film deposited on ceramic (Al2O3) substrate in the room temperature was investigated. Results show that studied material is sensitive to DMMP trace amounts and selective against acetone and methanol. It also exhibits fast response and recovery times, repeatability and short-term stability.

Study of Light-Activated Regioregular Poly(3-Hexyltiophene) Photoconductive Polymer Sensing Properties in Nerve Agent Simulant (DMMP) Detection

“…Considering 0.5% as the lowest detectable SR (the lowest value that was detectable above the noise for the studied structure, calculated as a standard variation in the signal), we obtained an LOD of 0.4 ppm. This value is lower than 1.1 ppm, which was obtained in the previous investigation [20] and is comparable with the LOD of the DMMP sensor based on poly(3-methyltiophene) which was reported by Ozturk et.al. [16].…”

“…The thick layer of RR-P3HT (with dimensions of 1.5 × 1.0 mm) was deposited by spray-coating method onto a porous FR4 laminate substrate using the procedure described in [20]. Before the P3HT deposition, the platinum interdigitated electrodes were deposited onto the substrate.…”

“…In our preliminary study [20], we reported the sensitivity of RR-P3HT to DMMP in room light conditions. In this work, we additionally activated it by using different LED illuminations, in order to enhance its sensing properties.…”

“…Consequently, its sensing properties can be enhanced by the light [19]. In a previous work [20], we presented the preliminary results of our investigations of the capability of RR-P3HT-activated using white light-of detecting DMMP. In this study, we activated the RR-P3HT films by means of a variety of light-emitting diodes with a wide spectrum of wavelengths.…”

“…The resistance of the deposited layer in dark conditions was on the order of G to T. For such a low dark conductance, measuring the sensing structure's electrical response becomes complex, since it requires an adequate picoammeter and the appropriate screening of the setup. Since, in the previous study [20], we observed the sensitivity of RR-P3HT to DMMP while illuminated by a white light, in this work we focused on the investigation of the influence of the applied wavelength on sensing responses.…”