Development of an Electrochemical Sensor Based on Molecularly Imprinted Polymer Using Functionalized Gold...

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Caffeine is a widely consumed alkaloid with stimulant and metabolic effects.
• Excessive caffeine intake (over 400 mg/day) can lead to adverse health effects.
• Accurate and selective caffeine quantification is crucial for monitoring consumption.

Purpose of the Study:

• To develop a novel electrochemical sensor for sensitive and selective caffeine quantification.
• To utilize a molecularly imprinted polymer (MIP) electropolymerized on gold nanoparticles (AuNPs) for caffeine detection.

Main Methods:

• Synthesis of AuNPs functionalized with p-aminothiophenol (AuNPs-pATP).
• Electropolymerization of MIP on AuNPs-pATP modified electrode.
• Characterization using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM).
• Caffeine quantification using square wave voltammetry (SWV).

Main Results:

• AuNPs-pATP exhibited spherical morphology (2.54 nm average diameter).
• MIP formation was confirmed by electrochemical techniques and SEM, showing specific cavities.
• The sensor achieved a low limit of detection (LOD) of 0.195 µmol L⁻¹ and limit of quantification (LOQ) of 0.592 µmol L⁻¹.
• High selectivity, reusability, reproducibility, and stability were demonstrated.

Conclusions:

• The developed MIP-based electrochemical sensor provides a sensitive, selective, and stable platform for caffeine quantification.
• The sensor shows potential for analyzing caffeine content in real-world samples like soft drinks and sports supplements.