Stable Pb ion-selective electrodes based on polyaniline-TiO solid contacts.

A novel Pb ion selective electrode based on a polyaniline-doped titanium dioxide (PANI-TiO) solid contact, denoted herein as GC/PANI-TiO/Pb-ISE, was successfully developed. The GC/PANI-TiO/Pb-ISE exhibited a stable and rapid potential response to Pb ions, with a linear response over the concentration range 10-10 M, a detection limit of ∼10 M and a response time of only 10-15 s. The PANI-TiO solid contact layer possessed a large specific capacitance, thereby effectively promoting ion-to-electron transduction and enhancing the output stability (potential drift, 122.6 μV/s). The developed electrode maintained excellent performance during continuous use, showing a linear response range of 10-10 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.