MWCNT/Nafion/Lead Ionophore Modified Electrode for The Detection of Trace Pb²⁺ in Coastal Seawater

Lead ions in coastal seawater will be enriched in marine organisms, further to endanger human health, so it is essential to conduct detection with high-sensitivity and high-selectivity for lead ions concentration in seawater. In this paper, multi-walled carbon nanotubes (MWCNT)/Nafion/lead ionophore electrode modification materials have been prepared therefore to obtain modified glassy carbon electrodes by a coating method. In order to define trace levels of Pb²⁺, differential pulse stripping voltammetry (DPSV) was used. Moreover, the experimental conditions i.e. accumulation potential, concentration, pH, accumulation time were in optimized condition. Thereby, results show that the peak current which was obtained in the range of 3~100 μg·L⁻1 for Pb²⁺ have a linear relationship with concentration corresponded, with the detection limits of 1.2 μg·L⁻1 for Pb²⁺. The modified electrode was used to determine the Pb²⁺ content in the coastal seawater of the Maowei Sea, and the recovery rate was between 90.4%~104.7%, which provided a novel approach of detection to define trace Pb²⁺ in seawater.