In Situ Preconcentration and Quantification of Cu²⁺ via Chelating Polymer-Wrapped Multiwalled Carbon Nanotubes

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Science

Background:

• Heavy metal detection in environmental matrices is challenging for traditional electrochemical sensors.
• Stripping voltammetry methods often struggle with selectivity and preconcentration in complex samples.

Purpose of the Study:

• To develop an electrochemical sensor for selective preconcentration of copper ions (Cu²⁺).
• To utilize chelating polymer-wrapped multiwalled carbon nanotubes (MWCNTs) for enhanced heavy metal detection.

Main Methods:

• Fabrication of a gold electrode modified with poly(ethylene terephthalate) (PET) and functionalized with poly-4-vinyl pyridine (P4VP)-wrapped MWCNTs.
• Electrochemical interrogation using cyclic voltammetry for Cu²⁺ ion analysis.
• Testing sensor performance in various water matrices (tap, lake, ocean, deionized).

Main Results:

• The sensor demonstrated selective preconcentration of Cu²⁺ ions via P4VP chelation.
• Achieved a detection limit of 0.5 ppm with a linear range of 1.1-13.8 ppm.
• Showed a low relative standard deviation (4.9%) at the EPA limit of 1.3 ppm, with consistent performance across different water types.

Conclusions:

• The P4VP-wrapped MWCNT sensor offers an effective platform for sensitive and selective Cu²⁺ detection.
• The developed preconcentration strategy is generalizable for heavy metal sensing in natural waters.
• This approach facilitates the design of continuous monitoring systems for environmental water quality.