CYP450 biosensors based on gold chips for antiepileptic drugs determination

Three-electrode configuration chips containing a Pt, Au and a screen-printed Ag/AgCl as counter, working and reference electrode, respectively, have been developed. Selective determination of Phenobarbital (PB) has been carried out by Cytochrome P450 2B4 (CYP450) immobilization into a polypyrrole matrix onto the gold working electrode. Chronoamperometric experiments show a PB diffusion coefficient of 2.42 × 10 −6 cm 2 s −1, a reproducibility and repeatability in terms of residual standard deviation (RSD) of 13% and 5.51%, respectively, and a limit of detection (LOD) of 0.289 μmol dm −3 ( α = β = 0.05) for the developed CYP450-biosensor chip. Its performance has been showed by the determination of PB in pharmaceutical drugs. HPLC has been used as reference technique.