A Simple Paper-Based Colorimetric Device for Rapid Mercury(II) Assay

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Mercury(II) ions (Hg2+) contamination is a significant environmental and health concern.
• Existing Hg2+ sensors often involve complex, time-consuming, and expensive procedures.
• There is a need for rapid, cost-effective, and accessible methods for Hg2+ detection.

Purpose of the Study:

• To develop a simple, rapid, and low-cost paper-based colorimetric device (PCD) for quantitative environmental analysis of Hg2+.
• To enable naked-eye detection of Hg2+ contamination.
• To provide a tool for field measurement of Hg2+.

Main Methods:

• A paper-based colorimetric device (PCD) was developed with pre-loaded 3,3,5,5-tetramethylbenzidine (TMB) substrate.
• Platinum nanoparticles (PtNPs) were added to sample solutions containing Hg2+.
• The interaction between Hg2+, PtNPs, and TMB was analyzed to determine Hg2+ concentration via color change intensity.

Main Results:

• PtNPs rapidly oxidized TMB, producing a blue color.
• Hg2+ ions interfered with PtNPs, suppressing TMB oxidation and reducing blue color intensity.
• The PCD allowed for naked-eye observation of Hg2+ presence and concentration.
• A fiber optic device enabled quantitative monitoring of Hg2+ down to 0.01 µM.

Conclusions:

• The developed paper-based colorimetric device (PCD) provides a simple, rapid, and cost-effective method for Hg2+ detection.
• The PCD facilitates naked-eye, quantitative analysis of Hg2+ in environmental samples.
• This technology holds significant potential for field-based Hg2+ monitoring and environmental assessment.