Novel therapeutic biosensor for indinavir-a protease inhibitor antiretroviral drug

An amperometric drug metabolism biosensor consisting of cytochrome P450-3A4 (CYP3A4) encapsulated in a didodecyldimethylammonium bromide (DDAB) vesicular system on a Pt disk electrode was developed for the determination of indinavir, a protease inhibitor antiretroviral drug. Cyclic, square wave and pulse voltammetric responses of the bioelectrode showed quasi-reversible electrochemistry of the Fe(3+)/Fe(2+) redox species of the heme thiolate CYP3A4 enzyme under aerobic and anaerobic conditions. The biosensor exhibited excellent response to indinavir with a detection limit and response time of 6.158 x 10(-2)mgL(-1), and 40s, respectively. The detection limit is well below the plasma concentration of indinavir (8h after intake) which range from 0.13 to 8.6mgL(-1).