Design, Preparation and Performance Study of On-Chip Flow-Through Amperometric Sensors with an Integrated Ag/AgCl
He Zhang1, Rongyan Chuai2, Xin Li3
1School of Information Engineering and Science, Shenyang University of Technology, Shenyang 110870, China. zhanghe@sut.edu.cn.
Micromachines
|November 15, 2018
Summary
A novel integrated Ag/AgCl reference electrode enhances on-chip amperometric sensor stability. This design, coupled with a flow-through sensor and microfluidic chip, improves trace metal detection in water.
Area of Science:
- Electrochemistry
- Microfluidics
- Analytical Chemistry
Background:
- On-chip amperometric sensors require stable reference electrodes for reliable measurements.
- Existing reference electrode designs can suffer from solution depletion, affecting long-term stability.
Purpose of the Study:
- To develop a novel integrated silver/silver chloride (Ag/AgCl) reference electrode structure for enhanced potential stability in microfluidic amperometric sensors.
- To design and optimize a flow-through amperometric sensor and microfluidic chip incorporating the integrated reference electrode.
- To improve the detection signal strength of the flow-through sensor through numerical simulation and structural design.
Main Methods:
- Integration of a self-refreshing Ag/AgCl reference electrode into a multilayer microfluidic chip.
- Design of a flow-through amperometric sensor.
- Numerical simulation to optimize detection cell geometry and sample flow rate.
- Trace detection of magnesium (Mg2+) and lead (Pb2+) ions.
Main Results:
- The integrated Ag/AgCl reference electrode structure demonstrated improved potential stability.
- Numerical simulations identified optimal parameters for signal enhancement: a step-type detection cell (200 μm × 200 μm × 100 μm) and controlled sample flow rate.
- Successful trace detection of Mg2+ at 5 μmol/L and Pb2+ at 84 μmol/L was achieved.
Conclusions:
- The novel integrated Ag/AgCl reference electrode design significantly enhances the stability of on-chip amperometric sensors.
- Optimized flow-through sensor design using a step-type cell and controlled flow rate boosts detection signal strength.
- The developed microfluidic device enables portable and sensitive trace metal detection, facilitating advancements in field analysis.
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