Polyindole-Derived Nitrogen-Doped Graphene Quantum Dots-Based Electrochemical Sensor for Dopamine Detection

Area of Science:

• Materials Science
• Electrochemistry
• Biomedical Engineering

Background:

• Dopamine (DA) level monitoring is crucial for diagnosing medical and behavioral issues.
• Existing methods for dopamine detection may lack sensitivity or selectivity.
• Development of efficient electrochemical sensors is needed for accurate dopamine level assessment.

Purpose of the Study:

• To synthesize nitrogen-doped graphene quantum dots (N-GQDs) from polyindole (PIN) using a facile hydrothermal method.
• To investigate the potential of N-GQDs as an electrochemical catalyst for sensitive dopamine detection.
• To evaluate the performance of N-GQDs-modified electrodes for dopamine sensing in real samples.

Main Methods:

• Synthesis of N-GQDs from PIN via a single-step hydrothermal process.
• Characterization of N-GQDs, including size (∼5.2 nm), C/N ratio (∼2.75%), and fluorescence properties.
• Fabrication of a N-GQDs-modified glassy carbon electrode (GCE) for electrochemical dopamine detection.
• Electrochemical analysis under optimized conditions to determine sensitivity, selectivity, and detection limits.

Main Results:

• Successfully synthesized N-GQDs with cyan fluorescence and N-doped graphitic lattices.
• N-GQDs exhibited enhanced electrocatalytic activity for dopamine detection.
• The N-GQDs-modified electrode demonstrated high sensitivity (0.15 nM detection limit) and a wide linear range (0.001–1000 µM).
• The sensor showed excellent selectivity and performance in real sample analysis.

Conclusions:

• N-GQDs synthesized from PIN serve as efficient electrochemical catalysts for dopamine detection.
• The developed N-GQDs-based electrochemical sensor offers superior sensitivity and selectivity.
• This technology shows promise for medical diagnostic applications requiring sensitive dopamine monitoring.