Portable Detection of Copper Ion Using Personal Glucose Meter

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Biotechnology

Background:

• Copper ions (Cu²⁺) are essential micronutrients but toxic at elevated levels, necessitating accurate detection methods.
• Existing methods for Cu²⁺ detection can be complex or require specialized equipment.
• Developing simple, sensitive, and portable detection systems is crucial for environmental monitoring.

Purpose of the Study:

• To develop a simple, sensitive, and portable method for detecting Cu²⁺.
• To utilize the Cu⁺-catalyzed alkyne-azide cycloaddition reaction for signal amplification.
• To integrate magnetic nanoparticles (MNPs) and a portable blood glucose meter (PGM) for a user-friendly assay.

Main Methods:

• Employed Fe₃O₄ magnetic nanoparticles (MNPs) as a reaction platform.
• Utilized gold nanoparticles (AuNPs) functionalized with glucose oxidase (GOx) and alkyne-modified DNA (C2).
• Leveraged the Cu⁺-catalyzed alkyne-azide cycloaddition reaction for capturing AuNPs onto azide-modified DNA on MNPs (C1) in the presence of Cu²⁺.

Main Results:

• Achieved a good linear relationship between the PGM response and the logarithm of Cu²⁺ concentration (0.05–10.00 μmol/L).
• Established a low detection limit of 0.03 μmol/L (3σ) for Cu²⁺.
• Demonstrated high accuracy and precision in real tap water samples, with recovery rates from 92.30% to 113.33% and RSD from 0.14% to 0.34%.

Conclusions:

• The developed method provides a simple, sensitive, and portable platform for Cu²⁺ detection.
• The combination of click chemistry, MNPs, and PGM offers a promising approach for environmental water quality monitoring.
• The assay meets the detection requirements for Cu²⁺ in real-world water samples.