A solid-contact Pb2+-selective electrode based on a hydrophobic polyaniline microfiber film as the ion-to-electron transducer

Abstract

Hydrophobic polyaniline-polystyrene microfiber films (e-PANI-PS) with a water contact angle of 104° were successfully prepared by electrospinning, then applied as a novel ion-to-electron transducer in solid-contact Pb2+ ion selective electrodes (Pb2+-ISEs). The GC/e-PANI-PS/Pb2+-ISE exhibited a wide linear Pb2+ detection range (10−8 to 10−3 mol L−1), a low detection limit (˜5 × 10−9 mol L−1), a Nernstian slope of 29.1 mV/decade and a fast response time (<10 s). Furthermore, the GC/e-PANI-PS/Pb2+-ISE fabricated using hydrophobic e-PANI-PS microfibers demonstrated a lower detection limit for Pb2+ and better stability compared with ISEs fabricated using PANI microfibers or drop-cast PANI-PS films as the ion-to-electron transducer. This superior performance of the e-PANI-PS microfiber transducer for Pb2+ detection can be attributed to its high hydrophobicity (which minimized water uptake), as well as its higher capacitance and lower impedance which promoted fast ion-to-electron transport. The GC/e-PANI-PS/Pb2+-ISE was applied to the measurement of Pb2+ concentrations in tap water samples, with the results obtained being in very good agreement with those of atomic absorption spectrometry (AAS) experiments, confirming the potential of the developed ISE for the fast analysis of lead ions in drinking water.