Microfluidic paper-based analytical devices and electromembrane extraction; Hyphenation of fields towards effective...

Area of Science:

• Analytical Chemistry
• Separation Science
• Microfluidics

Background:

• Electromembrane extraction (EME) is a powerful separation technique.
• Microfluidic paper-based analytical devices (μPADs) offer low-cost, portable analytical platforms.
• Integrating EME with μPADs can enhance analytical capabilities for field applications.

Purpose of the Study:

• To investigate the applicability of EME on customized μPADs for efficient analyte separation.
• To evaluate different electrode types and μPAD architectures (2D vs. 3D) for EME performance.
• To develop an integrated EME-μPAD system for colorimetric detection of copper ions.

Main Methods:

• Customized μPADs (2D and 3D origami) were fabricated.
• Electromembrane extraction was performed using stainless steel and paper-based electrodes.
• Copper ions were used as the model analyte for separation and colorimetric detection.
• Smartphone camera was utilized for signal readout.

Main Results:

• EME was successfully demonstrated on both 2D and 3D μPADs.
• 3D origami μPADs enabled effective EME at low applied voltage.
• Quantification of copper ions ranged from 40.0-1500.0 μg L⁻¹ with a limit of detection of 20.0 μg L⁻¹.
• The system showed compatibility with direct analysis of untreated human blood and spring water samples.

Conclusions:

• 3D origami μPADs integrated with EME provide an efficient and paper-compatible separation technique.
• The developed platform allows for sensitive, low-voltage, and portable analysis of copper ions.
• This approach demonstrates significant potential for direct analysis of real-world samples, including biological fluids.