Capillary and Electrodynamic Forces-Driven Separation Detection of Metal Ions Using a Disposable Microfluidic Sensor...

Area of Science:

• Analytical Chemistry
• Sensor Technology
• Environmental Science

Background:

• Heavy metal ion (HMI) contamination poses significant environmental and health risks.
• Accurate and sensitive detection methods are crucial for monitoring HMI levels in water.
• Microfluidic devices offer potential for portable and rapid HMI analysis.

Purpose of the Study:

• To develop a disposable microfluidic sensor for the precise separation and detection of multiple heavy metal ions.
• To optimize the sensor's performance by controlling electrodynamic forces, flow rates, and electrode modification.
• To validate the sensor's reliability by analyzing real water samples and comparing results with ICP-MS.

Main Methods:

• Fabrication of a disposable microfluidic channel sensor on a plastic platform.
• Application of AC potential to induce electrodynamic force for HMI separation.
• Modification of the working electrode with poly(diamino terthiophene) and graphene oxide (pDATT/GO) for enhanced detection.
• Optimization of experimental variables including AC frequency, amplitude, flow rate, pH, and temperature.

Main Results:

• Achieved precise separation and detection of multiple HMIs (Cu²⁺, Cd²⁺, Hg²⁺, Pb²⁺).
• Demonstrated linear dynamic ranges between 0.1 and 200.0 ppb with low detection limits (0.04–0.29 ppb).
• Validated the sensor's reliability through analysis of real water samples, showing excellent agreement with ICP-MS results (95% confidence level).

Conclusions:

• The developed disposable microfluidic sensor provides a sensitive, selective, and reliable platform for HMI analysis.
• The integration of electrodynamic force and modified electrodes significantly enhances separation and detection capabilities.
• This technology holds promise for portable and cost-effective environmental monitoring of heavy metal contamination.