Stable Pb2+ ion-selective electrodes based on polyaniline-TiO2 solid contacts

A novel Pb2+ ion selective electrode based on a polyaniline-doped titanium dioxide (PANI-TiO2) solid contact, denoted herein as GC/PANI-TiO2/Pb2+-ISE, was successfully developed. The GC/PANI-TiO2/Pb2+-ISE exhibited a stable and rapid potential response to Pb2+ ions, with a linear response over the concentration range 10(-3)-10(-9) M, a detection limit of similar to 10(-9.1) M and a response time of only 10-15 s. The PANI-TiO2 solid contact layer possessed a large specific capacitance, thereby effectively promoting ion-to-electron transduction and enhancing the output stability (potential drift, 122.6 mu V/s). The developed electrode maintained excellent performance during continuous use, showing a linear response range of 10(-3)-10(-7) M with no obvious changes in the potential response time or response slope (29 +/- 0.2 mV/decade) over six weeks. Results encourage the wider use of conducting polymer-semiconductor solid contacts in ion selective electrode development. (C) 2019 Elsevier B.V. All rights reserved.