Low-cost optical lifetime assisted ratiometric glutamine sensor based on glutamine binding protein

Area of Science:

• Biochemistry
• Analytical Chemistry
• Biomedical Engineering

Background:

• Glutamine is a crucial amino acid involved in various metabolic pathways.
• Accurate and sensitive detection of glutamine is vital for clinical diagnostics and biological research.
• Existing glutamine sensing methods often require complex instrumentation or reagents.

Purpose of the Study:

• To develop a novel reagentless fluorescence sensing technique for submicromolar glutamine detection.
• To implement a lifetime-assisted ratiometric sensing method for enhanced signal discrimination.
• To create a simplified and cost-effective optical sensing device for glutamine analysis.

Main Methods:

• Utilized a S179C mutant of glutamine binding protein (QBP) labeled with acrylodan and a europium(III) complex.
• Employed lifetime-assisted ratiometric sensing by modulating excitation light frequency.
• Discriminated fluorescence signals based on their distinct fluorescence lifetimes (nanoseconds vs. microseconds).

Main Results:

• Achieved reagentless, submicromolar detection of glutamine.
• Demonstrated successful discrimination of two fluorescence signals using minimal optical components.
• Showcased enhanced signal-to-noise ratio and simplified optical setup compared to traditional methods.

Conclusions:

• The developed lifetime-assisted ratiometric sensing technique offers a robust method for glutamine detection.
• The simplified optical setup and reagentless nature make the sensor suitable for low-cost applications.
• This technology has potential for point-of-care diagnostics and in-the-field analysis of glutamine.