Ionic liquid–polymer electrolyte for amperometric solid-state NO2 sensor

Abstract: A new ionic liquid–polymer electrolyte was successfully tested in the planar amperometric solid-state sensor sensitive towards nitrogen dioxide. The electrolyte consists of 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) in the ratio 57:43mol.% and exhibits ionic conductivity 1.6×10−4 Scm−1 at 20°C, high electrochemical stability (over 4V on gold or glassy carbon) and thermal stability (over 230°C). The analyte, gaseous nitrogen dioxide in air, was determined using the electrochemical reduction at −900mV vs. Pt/air on gold minigrid indicating electrode with Pt/air as a reference electrode. The sensor response is linear in the NO2 concentration range 0.3–1.1ppm and is reproducible and long-term stable. [Copyright &y& Elsevier]