Luminescence Lifetime-Based Sensing of Water Turbidity

Area of Science:

• Analytical Chemistry
• Environmental Science
• Sensor Technology

Background:

• Commercial turbidity sensors are often expensive, bulky, and fragile.
• Accurate turbidity measurement is crucial for water quality assessment.
• Research is ongoing to develop alternative, more robust sensing methods.

Purpose of the Study:

• To develop and characterize a novel luminescence-based sensor for water turbidity.
• To utilize a dual-lifetime reference scheme for enhanced measurement accuracy.
• To provide a cost-effective and potentially more robust alternative to existing sensors.

Main Methods:

• A dual-lifetime luminescence referencing scheme was employed.
• A reference fluorophore (BCT in PVC) and an indicator luminophore (RD3 in PCA) were used.
• The sensor measures the luminescence phase shift caused by turbidity as water flows between dye layers.

Main Results:

• The sensor accurately detects turbidity in ranges of 0-1000 NTU, 0-500 NTU, and 0-300 NTU for different optical pathlengths (1-2 cm).
• Achieved accuracy is 1 NTU (0.3 NTU between 0-10 NTU).
• The sensor demonstrated instantaneous, temperature-independent response, free from dissolved oxygen and chlorophyll interference, and performed well over 11 days in real-world conditions.

Conclusions:

• The developed luminescence sensor provides a viable, accurate, and potentially more robust method for water turbidity monitoring.
• The dual-lifetime referencing scheme effectively translates turbidity into measurable luminescence phase shifts.
• The sensor's performance in real-world conditions indicates its practical applicability for water quality assessment.