Automatic microfluidic fluorescence-array measurement system for detecting organic phosphate.

Area of Science:

• Analytical Chemistry
• Biomedical Engineering
• Environmental Science

Background:

• Organic phosphate pesticides pose risks to human health and the environment.
• Accurate and efficient detection methods are crucial for monitoring pesticide residues.
• Existing detection methods can be costly, time-consuming, and require large sample volumes.

Purpose of the Study:

• To develop an automatic microfluidic fluorescence-array measurement system for detecting organic phosphate concentration.
• To improve detection speed, accuracy, and precision while reducing sample quantity and cost.
• To validate the system's performance using common organic phosphate pesticides.

Main Methods:

• Development of an integrated microfluidic fluorescence-array system.
• Utilizing a luminol-hydrogen peroxide catalytic fluorescent mechanism for detection.
• Incorporating a CCD image module, stepper motor, and dynamic image analysis.
• Testing with chlorpyrifos and fenitrothion as model organic phosphate pesticides.

Main Results:

• The system requires only 2.5 μl of sample with a rapid 1.4-second response time.
• Achieved sensitivities of 1.88 V/ppm for chlorpyrifos (0.166–10 ppm range) and 0.32 V/ppm for fenitrothion (0.03–10 ppm range).
• Demonstrated low average errors of 1.66% and 1.68% for chlorpyrifos and fenitrothion, respectively.
• The detection range covers legal limits for pesticide residues.

Conclusions:

• The developed automatic microfluidic system offers a sensitive, accurate, and efficient method for detecting organic phosphate pesticides.
• This technology has the potential to significantly enhance pesticide residue monitoring in various matrices.
• The system's advantages in reduced sample volume, cost, and time make it suitable for widespread application.