In recent times, there has been an increasing demand for inexpensive, accurate, movable and reliable gas sensors that can differentiate between very low concentrations of analytes. Conductive polymers (CPs) such as indole are being explored as promising materials for micro sensors, because of their ability to form a good basis for premise chemical sensors either as a sensing element or as a matrix to deactivate specific analytes. In our previous work the chemical, morphological and electrical characterisation of the Polyindole/Dioxynucleic Acid (Pln/DNA) nanowires have shown the formation of a smooth hybrid material with good electrical conductivity. In this research work, we report the development of a gas sensor based on Pln/DNA nanowires for the detection of volatile organic compounds (VOCs) at room temperature. For the response time, chloroform (104s) takes the longest time to respond when exposed to the Pln/DNA bulk nanowires while ethanol and hexane both have responses time of less than 80s. While for the recovery time, ethanol (65s) was recovered faster than all the other VOCs while acetone (93), chloroform (98) and methanol (91). Overall, response time is very fast in comparison with the recovery time. Measurement of response time revealed ethanol to have the highest ratio (1.0) and hexane (0.71) have the least values. On the other hand, the highest baseline drift value was observed in chloroform (1.5) while the least of 1.0 was recorded for propanol. Finally, for the sensitivity, Hexane (0.58) has the lowest towards the Pln/DNA nanowires, while methanol has the highest (1.3). The result suggests the possibility of using the Plm/DNA sensor for measuring VOCs at room temperature.

Keywords: sensing, polymer, selectivity, temperature analytes