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Journal of Chemistry
Volume 2015, Article ID 630408, 7 pages
Research Article

Conductive Composite Biosensor System for Electrochemical Indinavir Drug Detection

SensorLab, Department of Chemistry, University of Western Cape, Private Bag X17, Bellville 7535, South Africa

Received 3 July 2015; Accepted 26 August 2015

Academic Editor: Josefina Pons

Copyright © 2015 Natasha Ross et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Indinavir is a protease inhibitor antiretroviral (ARV) drug, which forms part of the highly active antiretroviral therapy during the treatment of HIV/AIDS. Indinavir undergoes first-pass metabolism through the cytochrome P450 (CYP) enzymes in the human liver, of which CYP3A4 is the most influential isoenzyme. Multidrug combination therapy and, as such, therapeutic drug monitoring (TDM) during HIV/AIDS treatment are therefore critical, to prevent adverse interactions. The conventional sensitive and specific assays available for quantifying ARV drugs, however, suffer from distinct disadvantages. In this regard, biosensors can be used to provide real time information on the metabolic profile of the drug. In this study, a biosensor with cobalt(III) sepulchrate trichloride as diffusional mediator was constructed. The biosensor platform consisted of CYP3A4 immobilized onto a gold nanoparticle (GNP) overoxidized polypyrrole (OvOxPpy) carrier matrix. The biosensor exhibited reversible electrochemistry, with formal potential determined as −624 ± 5 mV, from voltammetric analysis, with overall electron transfer being diffusion controlled. The biosensor showed typical electrocatalytic response to dioxygen (O2), exemplified by the distinct increase in the cathodic peak current (). A concentration-dependent increase in was observed in response to consecutive additions of Indinavir.