Optical ATP biosensor for extracellular ATP measurement.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biophysics

Background:

• Extracellular Adenosine-5'-triphosphate (ATP) is a key signaling molecule mediating physiological activities via purinergic P2 receptors.
• Accurate in-situ measurement of extracellular ATP in biological tissues is crucial for understanding various physiological and pathological processes.

Purpose of the Study:

• To develop a novel optical sensor for real-time, in-situ measurement of extracellular ATP concentrations within biological tissues.
• To validate the sensor's performance across a broad concentration range and assess its robustness against environmental factors.

Main Methods:

• Fabrication of an optical ATP sensor using a dual-layer sol-gel coating on an optical fiber probe.
• Incorporation of a ruthenium complex for oxygen sensing and enzymes (glycerol kinase, glycerol 3-phosphate oxidase) for ATP oxidation.
• Development of an oxygen compensation method to ensure accurate ATP quantification under varying oxygen levels.

Main Results:

• The optical ATP sensor demonstrated reliable detection of ATP across a wide concentration range (10⁻³ mM to 1.5 mM).
• The sensor successfully measured extracellular ATP in biological tissue samples (porcine intervertebral disc).
• Performance was unaffected by variations in pH and the presence of extracellular ATP derivatives.

Conclusions:

• The developed optical ATP sensor provides a robust and accurate tool for in-situ extracellular ATP measurement.
• This technology offers a valuable option for researchers studying ATP's role in biological systems and disease.
• The sensor's stability and specificity enhance its utility for complex biological sample analysis.