Exploring a novel, sensitive, and efficient Pb2+ electrochemical sensing strategy based on Cu-MOF

Abstract

Lead (Pb) pollution is a wide and severe public health issue, and developing efficient detection method for lead ion (Pb2+) is of crucial importance. Herein, a 2,5-dimercapto-1,3,4-thiadiazole (DMTZ)-functionalized hydroxycopper salt metal organic framework (MOF) material (named as DMP-Cu) was prepared through an in-situ self-templating method and used to develop an electrochemical sensor for the detection of Pb2+. The successful synthesis of the composite DMP-Cu was confirmed by X-ray diffraction, scanning electron microscopy, and X-ray energy spectroscopy. After optimization of the detection conditions, the DMP-Cu-50 modified glassy carbon electrode (DMP-Cu-50/GCE) shows good sensing performance to Pb2+ in aqueous solutions via square wave anodic dissolution voltammetry. The modified electrode exhibited good conductivity and the oxidation current showed a linear relationship to Pb2+ in the ranges of 1 × 10-11 ∼ 4 × 10-10 mol·L-1 and 8 × 10-10 ∼ 5 × 10-8 mol·L-1 with a detection limit of 0.003 nmol·L-1. In addition, the proposed sensing platforms have good reproducibility, stability, and anti-interference properties. With further analysis of real samples, the proposed sensors exhibit satisfactory performance in detecting Pb2+ in multiple actual water samples, including tap water and pond water. Therefore, the novel sensor can be a powerful analytical strategy for Pb2+ and has high potential to aid the effective monitoring and risk assessment of Pb2+ in the environment.

Keywords

• MOFs
• Electrochemical sensor
• Environmental analysis
• Heavy metals
• Lead
• Dissolution voltammetry