Development of a Potential-Modulated Electrochemiluminescence Measurement System for Selective and Sensitive...

Area of Science:

• Analytical Chemistry
• Forensic Science
• Electrochemistry

Background:

• Codeine, an analgesic and pro-drug of morphine, poses a high risk of abuse due to its widespread availability as an over-the-counter (OTC) drug.
• Sensitive and selective screening methods for codeine are essential in forensic analytical chemistry.
• A lack of commercial analytical kits necessitates field-deployable methods for codeine quantification.

Purpose of the Study:

• To develop a sensitive and selective analytical method for codeine determination.
• To enable field quantification of codeine in prescription and OTC drug samples.
• To explore the application of potential modulation combined with electrochemiluminescence (ECL) for codeine analysis.

Main Methods:

• Utilized potential modulation, superimposing AC potential on DC potential, applied to electrodes.
• Employed tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)₃]²⁺) as an electrochemiluminescence (ECL) emitter.
• Investigated the electrochemical reaction mechanism, focusing on the oxidation of the opioid framework.

Main Results:

• Confirmed ECL activity for codeine, with selective detection observed in acidic solutions.
• The potential modulated-ECL method demonstrated one order of magnitude higher sensitivity compared to conventional potential sweep methods.
• The method achieved a low detection limit of 150 ng/mL and showed good linearity when applied to real drug samples.

Conclusions:

• Potential modulated ECL is a highly sensitive and selective technique for codeine determination.
• The developed method is suitable for quantifying codeine in prescription and OTC medications.
• This approach addresses the need for field-deployable analytical tools for codeine screening.