Tripartite Detection and Sensing of Toxic Heavy Metals Using a Copper-Based Porphyrin Metal-Organic Framework

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Heavy metal detection in water is vital for environmental and public health.
• Existing electrochemical sensors have limitations like high detection limits and poor selectivity.

Purpose of the Study:

• To develop a sensitive and selective electrochemical sensor for detecting lead (Pb2+), cadmium (Cd2+), and mercury (Hg2+).
• To explore the use of copper (Cu) metal-organic frameworks (MOFs) with replaced Cu metal nodes for heavy metal sensing.

Main Methods:

• Fabrication of a working electrode using copper-tetracarboxyphenylporphyrin (Cu-TCPP) sheets adsorbed on a glassy carbon electrode (GCE).
• Electrochemical detection of heavy metals based on their adsorption and oxidation within the Cu-MOF structure.
• Analysis of oxidation peak currents for quantitative detection and assessment of sensing range and limit of detection (LoD).

Main Results:

• The Cu-TCPP modified GCE demonstrated quantitative detection of Pb2+, Cd2+, and Hg2+.
• Achieved an ultralow LoD of up to 5 nM with a sensing range up to 30 μM.
• Exhibited robust and selective sensing capabilities with minimal error (<10%) in the presence of interfering ions.

Conclusions:

• This work presents the first Cu-TCPP modified GCE anode for sensitive multi-heavy metal detection.
• The study provides insights into the Cu replacement kinetics within the Cu-MOF structure.
• The developed sensor shows significant potential for accurate and reliable heavy metal monitoring in water sources.