Electrochemical determination of cocaine using screen-printed cytochrome P450 2B4 based biosensors

• Published in: Talanta (Oxford) 2013-02, Vol.105, p.131-134
• Main Authors: Asturias-Arribas, Laura, Alonso-Lomillo, M. Asunción, Domínguez-Renedo, Olga, Arcos-Martínez, M. Julia
• Format: Article
• Language: English
• Subjects: Aryl Hydrocarbon Hydroxylases - metabolism; Biosensing Techniques; Cocaine; Cocaine - analysis; Cytochrome P450 2B4; Cytochrome P450 Family 2; Electrochemical Techniques; Enzymatic biosensor; Screen-printed electrodes
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2012.11.078

This paper describes the development of screen-printed cytochrome P450 2B4 based biosensors, from the fabrication of the device using a single screen-printing technology to its characterization and application in the determination of cocaine street samples. Voltammetric measurements were first performed in order to study the electrochemical behavior of the enzyme trapped in the structure of the working electrode, as well as its interaction with one of its substrates, cocaine. Then, chronoamperometric measurements were carried out for the characterization of the biosensors. Calibration curves under optimum conditions of the experimental variables have been used for establishing the reproducibility (5.91%, n=5), the repeatability (10.45%, n=3) and the capability of detection (0.2mM, α=β=0.05) of the described method in the calibration range from 0.2 to 1.2mM. Finally, the performance of the developed biosensors has been successfully probed by the analysis of the purity of cocaine street samples. ► CYP450 2B4 based biosensors have been developed for cocaine determination. ► The enzyme has been directly screen-printed onto the surface of SPCEs. ► The developed procedure has shown a reproducibility of 5.91% (n=5). ► A capability of detection of 0.2mM for α=β=0.05 has been yielded. ► The biosensors have been successfully applied to the analysis of cocaine samples.