Polypyrrole/Graphene Quantum Dot Composites as a Sensor Media for Epinephrine

Area of Science:

• Materials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Epinephrine (EP) is a crucial hormone and neurotransmitter.
• Accurate detection of EP is vital for diagnosing and managing various medical conditions.
• Existing EP detection methods can be complex or time-consuming.

Purpose of the Study:

• To develop a simple, rapid, and sensitive biosensor for epinephrine detection.
• To utilize polypyrrole/graphene quantum dot (PPy/GQD) composites for enhanced fluorescence properties.
• To validate the biosensor's performance in complex biological matrices like human serum.

Main Methods:

• Synthesis of PPy/GQD composites, leveraging amine groups on PPy for GQD passivation.
• Exploitation of fluorescence quenching mechanism (photoinduced electron transfer) for EP detection.
• Calibration of the biosensor using varying EP concentrations (0.7–400 μM) and analysis of human serum samples.

Main Results:

• PPy/GQD composites exhibited significantly enhanced fluorescence emission (up to three times that of pristine GQDs).
• Epinephrine triggered fluorescence quenching of PPy/GQD composites in neutral to alkaline solutions.
• A linear relationship was observed between quenched fluorescence intensity and EP concentration.
• Satisfactory results were obtained when determining EP concentration in human serum samples.

Conclusions:

• The developed PPy/GQD composite-based biosensor provides a simple and rapid method for epinephrine detection.
• The fluorescence quenching mechanism offers a sensitive approach for EP quantification.
• The biosensor demonstrates potential for practical application in clinical diagnostics, specifically for EP determination in human serum.