A selective distance-based paper analytical device for copper(II) determination using a porphyrin derivative

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Accurate detection of copper (Cu2+) in water is crucial for public health and environmental monitoring.
• Existing methods for Cu2+ detection can be complex, time-consuming, or require specialized equipment.
• Development of simple, selective, and sensitive analytical tools for on-site water quality assessment is needed.

Purpose of the Study:

• To synthesize and characterize Meso-tetrakis(1,2-dimethylpyrazolium-4-yl)porphyrin sulfonate (TDMPzP) as a colorimetric reagent.
• To develop a microfluidic paper-based analytical device (µPAD) for selective and sensitive Cu2+ detection using TDMPzP.
• To evaluate the performance of the TDMPzP-based µPAD for real-time Cu2+ monitoring in drinking water.

Main Methods:

• Synthesis of the water-soluble porphyrin derivative, TDMPzP.
• Fabrication of a distance-based µPAD for colorimetric Cu2+ quantification.
• Optimization of reaction conditions (e.g., pH) and assessment of selectivity against common metal ions.
• Validation using real drinking water samples and comparison with Inductively Coupled Plasma Mass Spectrometry (ICP-MS).

Main Results:

• TDMPzP exhibited high selectivity for Cu2+ in aqueous solutions, producing a visible color change from green to pink under acidic conditions.
• The optimized distance-based µPAD demonstrated good analytical response and a limit of detection of 1 mg/L (1 ppm) for Cu2+.
• The system showed no significant interference from other common metal ions, meeting US EPA and WHO drinking water guidelines.
• Analysis of real water samples showed excellent agreement with ICP-MS results, confirming practical applicability.

Conclusions:

• The developed TDMPzP-based µPAD is a convenient, effective, and selective tool for the real-time detection of Cu2+ in drinking water.
• This approach offers a promising alternative for on-site water quality monitoring, addressing the need for rapid and reliable analytical methods.