Effect of Ultraviolet Activation on Sub-ppm NO2 Sensing Dynamics of Poly(3-hexylthiophene)-Bearing Graft Copolymers

Abstract

Nitrogen dioxide (NO2) sensors utilising graft copolymers bearing poly(3-hexylthiophene) chains have been developed and investigated in terms of their operation parameters using different carrier gases (N2 or air) and in either dark conditions or with ultraviolet (UV) irradiation. Interestingly, sensor performance improved upon transition from N2 to air, with the inverse being true for most NO2 sensors. UV irradiation both improved sensor dynamics and stabilised the sensor electrical baseline, allowing sensors based on SilPEG to fulfil the requirements of sensing solutions used in industry (below 10% baseline drift after sensors reach saturation) and making them promising candidates for further development and applications. Based on conducted multi-variate experiments, an initial mechanism underlying the interplay of exposure to oxygen (present in air) and UV irradiation was postulated.

Advances in the Use of Conducting Polymers for Healthcare Monitoring

“…Notably, CPs are emerging as pivotal materials for biosensors, and they are likely to attract investment in various fields. Some well-known CPs, including polyacetylene [36], polydi-acetylenes [37], polyaniline [38], polypyrrole [39], polythiophene [40], poly(3,4-ethylenedioxythiophene) [41], poly(phenylene vinylene) [42], poly(3-hexylthiophene-2,5-diy [43], polyindole [44], poly(p-phenylene) [45], poly(3-alkylthiophene) [46], poly(p-phenyleneterephthalamide) [47], poly(isothianaphthene), poly(α-naphthylamine), polyazulene [48], polyfuran, polyisoprene [49], polybutadiene [50], poly(3-octylthiophnene-3-methylthiophene) [51], polyorthotoluidiene [52], poly (dioctylfluorene) [53], poly(p-phenyleneethynylene) [54], polyphenylene sulfide [55], and poly(triaryl amine) [56], have found diverse applications in the physicochemical interface. Figure 2 illustrates 20 popular types of CPs used in sensors.…”