Polypeptide Functional Surface for the Aptamer Immobilization: Electrochemical Cocaine Biosensing

Area of Science:

• Analytical Chemistry
• Biosensors
• Electrochemistry

Background:

• Electroanalytical technologies are vital for abused drug analysis.
• Aptamer-based biosensors offer selectivity, miniaturization, automation, and cost-effectiveness.

Purpose of the Study:

• To develop a novel aptamer-based biosensing procedure for cocaine detection.
• To combine aptamers with electroanalytical techniques for sensitive drug analysis.

Main Methods:

• Fabrication of an electrode surface coated with polythiophene bearing polyalanine (PT-Pala).
• Covalent attachment of cocaine aptamer to the PT-Pala modified electrode.
• Electrochemical characterization to confirm surface modification.

Main Results:

• The aptasensor successfully detected cocaine and its metabolite, benzoylecgonine (BE).
• Linear correlation observed for cocaine (2.5–10 nM) and BE (0.5–50 μM).
• Method validated for analysis in synthetic biological fluids.

Conclusions:

• The developed aptasensor is a sensitive and selective tool for cocaine and BE detection.
• This method holds potential for practical application in abused drug analysis.
• The integration of aptamers and electroanalytical methods offers a promising platform for biosensing.