Selective and sensitive electrochemical determination of Pb2 + based on highly adsorptive WOx–ethylenediamine nanowires

• A modified electrode for Pb2 + detection is constructed using WOx–EDA hybrid nanowires.
• WOx–EDA nanowires with lamellar mesostructure possess high surface-to-volume ratio.
• The chelating between –NH2 and Pb2 + leads to high selectivity of the modified electrode to Pb2 +.
• The proposed electrochemical method can detect Pb2 + in real samples with good accuracy.

Inorganic–organic hybrid WOx–ethylenediamine (WOx–EDA) nanowires with high surface-to-volume ratio and abundant amino groups were synthesized for selective and sensitive electrochemical determination of Pb2 +. The WOx–EDA nanowires possessed a uniform lamellar mesostructure and could disperse evenly in Nafion solution for preparation of WOx–EDA modified electrode with good reproducibility. The modified electrode showed selective response toward Pb2 + due to the chelating between amino groups and Pb2 +. The electrochemical characterization and detection of bound Pb2 + were performed by square wave anodic stripping voltammetry. Under optimized conditions, the WOx–EDA-based sensor could detect Pb2 + directly from 0.01 to 10 μM with a detection of limit down to 3.2 nM. The proposed sensor with WOx–EDA hybrid nanowires exhibited good selectivity and sensitivity, and acceptable stability and reproducibility, showing promising practical application in Pb2 + determination.