Detecting Isotachophoresis Zones Hidden in Noise Using Signal Processing

Area of Science:

• Analytical Chemistry
• Microfluidics
• Biochemical Sensing

Background:

• Lowering the limit of detection (LOD) is crucial for expanding sensing applications.
• Increased instrumentation is typically required to improve LOD, limiting commercial viability.

Purpose of the Study:

• To demonstrate signal-to-noise ratio enhancement in microfluidic sensing via signal postprocessing.
• To reduce the limit of detection without additional hardware.

Main Methods:

• Utilized isotachophoresis (ITP) with fluorescence detection on a microfluidic chip.
• Applied postprocessing techniques to recorded fluorescence images, leveraging electrophoretic transport physics and noise structure.

Main Results:

• Achieved a 2-orders-of-magnitude reduction in detectable concentration by processing 200 images compared to a single image.
• Demonstrated signal-to-noise ratio improvement is proportional to the square root of the number of processed images.

Conclusions:

• Signal postprocessing offers a cost-effective method to enhance microfluidic sensor performance.
• The developed technique allows for significant LOD reduction, paving the way for detecting minute sample amounts in various applications.