Differential pulse voltammetry and chronoamperometry as analytical tools for epinephrine detection using a...

Area of Science:

• Electrochemistry
• Biosensor Technology
• Neurotransmitter Analysis

Background:

• Epinephrine (EP) is a crucial neurotransmitter with significant diagnostic implications.
• Accurate and sensitive detection methods for EP are vital in clinical and pharmaceutical settings.
• Existing detection methods often face challenges with sensitivity, selectivity, and complex sample matrices.

Purpose of the Study:

• To design and optimize a biosensor for sensitive and selective epinephrine detection.
• To compare differential pulse voltammetry (DPV) and chronoamperometry (CA) for optimal electroanalytical performance.
• To evaluate the biosensor's stability, selectivity, and applicability in real pharmaceutical samples.

Main Methods:

• Fabrication of a biosensor using a poly-thiophene derivative and tyrosinase immobilized on an electrode surface.
• Comparative analysis of DPV and CA electroanalytical techniques for EP detection.
• Characterization of biosensor performance including linear range, detection limit, sensitivity, stability, and selectivity.
• Application of the optimized biosensor for EP determination in a pharmaceutical formulation.

Main Results:

• The DPV technique demonstrated a wide linear range (1-20 μM and 30-200 μM) and low detection limits (0.18 nM and 1.03 nM) for EP.
• CA exhibited a narrower linear range (10-200 μM) and a higher detection limit (125 nM) with lower reproducibility.
• The optimized DPV-based biosensor showed excellent sensitivity (0.0011 μA mM⁻¹ cm⁻²), stability (49 days), and selectivity against common interferents.
• The biosensor successfully quantified EP in a pharmaceutical sample, demonstrating practical applicability.

Conclusions:

• The developed poly-thiophene/tyrosinase biosensor coupled with DPV is a highly effective system for epinephrine detection.
• DPV offers superior performance compared to CA for this specific biosensing application.
• The biosensor exhibits promising characteristics for reliable EP monitoring in pharmaceutical analysis.