Polyaniline on Poly (3,4-ethylenedioxythiophene) Screen Printed Electrode as Dissolved Ammonia Sensor

Abstract

Abstract Polyaniline (PANI) is a suitable material to be used as sensor for dissolved ammonia (DA) detection. PANI has conducting properties based on the fact that PANI structure contains pi (π) electron. In this study, polyaniline was synthesized from aniline monomer by cyclic voltammetry method on Poly (3,4-ethylenedioxythiophene) (PEDOT) screen printed electrode (SPE). The optimum concentration of aniline monomer was 0.5 M in 1.0 M sulphuric acid (H2SO4) which gave the highest current density (38 mAcm-2) upon electropolymerization on PEDOT SPE. The deposition of emeraldine salt (ES) of PANI was observed at +0.5 V (oxidation) and -0.2V (reduction). ES was then reacted with DA producing emeraldine blue (EB). The calibration of PANI sensors to DA solution (10 - 250 ppb) showed that the current density increased linearly with the rising trace amount of DA concentration. In terms of reproducibility, PANI sensor showed consistency in DA detection of 7.47 % deviation of mean current density readings towards 10 ppb DA solution. Here, PANI-PEDOT DA sensor was able to detect the trace DA concentration (10 ppb) which Nessler method unable to detect at this very low concentration of DA. Hence, this sensor was applied in DA detection in fish aquarium water samples. Thus, PANI-PEDOT SPE was able to perform as a DA sensor and can be further developed and commercialized for future uses.