Sensores semicondutores poliméricos planares para detecção de amônia

Abstract

This work’s main goal is to build, characterize and improve devices for the detection of ammonia in a given ambient using polyaniline as the sensitive layer allied with reduced graphene oxide to improve the sensor’s performance. The architecture of the device is based on a dielectric phenolic resin coated with an interdigitated electrode array made of copper. On this electrode array, a sensitive layer composed between polyaniline and reduced graphene oxide is deposited. Absorbance and microscopy studies were done in order to study the thin film behavior, as well as electrical measurements to analyze the interaction between both materials. Tests using ammonia were carried on a closed ambient chamber in order to evaluate the sensor’s performance. The device presented an improvement when rGO was added into the polymer’s matrix, where a reduction in response time, an increase in sensibility and the capability to return to its baseline were noticed. The proposed architecture showed promising results performance-wise when compared to other sensors published in the literature that uses more expensive materials like gold, silver and platinum electrodes as well as more refined techniques that results in an increase in the device’s final cost.