Investigation of electrochemical behaviour of polyaniline on carbon screen-printed electrodes for the detection of nitrite

The existence of nitrite in food, water and environment can cause toxic effects on humans and there is a need for detection. Several approaches such as optical, chromatography and electrochemical techniques have been followed to detect nitrite. Electrochemical sensors are attractive because of their ease of preparation, low cost, fast response time and on/field measurement ability. We introduce the use of polyaniline polymer and carbon screen-printed electrode for detection of nitrite. Polyaniline is a conducting polymer with high environmental stability and conducting properties. The working electrode was electrochemically polymerized in different acid solutions. Here we show the effect of the different acids on the electro polymerization of aniline towards the electrochemical sensing properties for nitrite. It was investigated that polymerization in sulphuric acid was found to achieve the best sensitivity towards nitrite detection. The effect of number of scans and scan rate of electropolymerization had a significant effect on the detection of nitrite.