A Polydopamine-Based Molecularly Imprinted Electrochemical Sensor for Fentanyl Determination

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Fentanyl's illicit use necessitates rapid and reliable detection methods.
• Existing detection techniques can be time-consuming or require specialized equipment.
• Development of portable electrochemical sensors offers a promising alternative for on-site analysis.

Purpose of the Study:

• To develop a molecularly imprinted polymer (MIP)-based electrochemical sensor for the rapid and selective detection of fentanyl.
• To optimize the sensor's performance and evaluate its stability and selectivity.
• To assess the sensor's applicability in complex matrices like artificial urine.

Main Methods:

• Fabrication of a screen-printed electrode modified with carbon nanofiber-Pt nanoparticle composite.
• Electrochemical grafting of polydopamine to create a MIP layer using fentanyl as a template.
• Characterization of the sensor using spectroscopy, microscopy, and electrochemical techniques.
• Optimization of sensor parameters and evaluation of binding kinetics via Langmuir-Freundlich isotherm.

Main Results:

• The MIP sensor exhibited a dissociation constant (kd) of 16.13 μM and a limit of detection of 0.094 μM for fentanyl.
• Demonstrated good run-to-run repeatability (RSD 6.7%) and batch-to-batch reproducibility (RSD 9.1%).
• Showcased excellent storage stability for 4 weeks (RSD ≤10%) and high selectivity against structurally similar compounds and in artificial urine.

Conclusions:

• The developed MIP electrochemical sensor provides a sensitive, selective, and stable platform for rapid fentanyl detection.
• The sensor's performance in artificial urine suggests its potential for practical forensic and clinical applications.
• This technology represents a significant advancement in portable analytical devices for controlled substance monitoring.