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Updated: May 12, 2026
10:13
Fentanyl Analog Screening using LC-TIMS-TOF MS/MS
Published on: November 8, 2024
Resolving Signal Overlap in Fentanyl and Cocaine Detection Using Dual-pH Differential Pulse Voltammetry in Illicit
Ahmed A Khorshed1, Alyaa Selim2, Alexander J Peltekoff3
1Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, ON K1N 6N5, Canada.
ACS Sensors
|May 11, 2026
Summary
A new electrochemical sensor can rapidly detect fentanyl and cocaine together, even when mixed. This dual-pH method improves drug testing accuracy for harm reduction and forensic applications.
Area of Science:
- Electrochemistry
- Analytical Chemistry
- Materials Science
Background:
- Fentanyl and cocaine co-adulteration poses significant risks, complicating user experience, dosing, and harm reduction strategies.
- Accurate, simultaneous detection of these drugs is crucial for public health and forensic analysis but challenging due to overlapping signals.
- Existing drug-testing tools struggle with the complexity of mixed fentanyl and cocaine samples.
Purpose of the Study:
- To develop a rapid, selective, and sensitive electrochemical sensing method for the simultaneous detection of fentanyl and cocaine.
- To address the limitations of current analytical techniques in identifying co-occurring fentanyl and cocaine in street samples.
- To provide a tool for enhanced harm reduction and forensic investigations involving these substances.
Main Methods:
- Utilized screen-printed electrodes (SPEs) modified with sodium dodecyl sulfate (SDS).
- Employed differential pulse voltammetry (DPV) with a novel dual-pH strategy (pH 4.5 and pH 10).
- Developed a method to selectively detect fentanyl at pH 4.5 and quantify both drugs at pH 10, enabling indirect cocaine determination.
Main Results:
- Achieved low limits of detection (LODs): 2.67 μM for fentanyl (pH 4.5), 2.89 μM for fentanyl (pH 10), and 1.28 μM for cocaine (pH 10).
- Demonstrated high sensitivity, selectivity, and reproducibility when tested on real-world street drug samples.
- Validated the sensor's performance against gas chromatography-mass spectrometry (GC-MS) for accurate cocaine and semi-quantitative fentanyl determination.
Conclusions:
- The developed electrochemical sensor offers a reliable method for the rapid, simultaneous detection of fentanyl and cocaine in complex mixtures.
- This technology supports improved on-site drug screening, aiding harm reduction efforts and forensic analysis.
- The dual-pH strategy effectively overcomes signal interference, providing accurate quantification in adulterated samples.
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