Application of a transition metal oxide/carbon-based nanocomposite for designing a molecularly imprinted poly (l-cysteine) electrochemical sensor for curcumin

Abstract

In this study an electrochemical sensor was fabricated for detection of curcumin, as a functional herbal food, using molecularly imprinted polymer and highly conductive transition metal oxide/carbon-based nanocomposite. In this way, CuCo₂O₄/nitrogen-doped carbon nanotubes/phosphorus-doped graphene oxide nanocomposite was dropped on the electrode. This nanocomposite synergically possesses conductivity features of copper and phosphorus-doping sites, specific surface area of carbon nanotubes, and carbons Fermi level of graphene oxide. In the following, l-Cystein electropolymerized on the electrode in presence of curcumin. The sensor was produced by removing curcumin from poly (L- cystein) matrix. The sensor was successfully used for detection of curcumin in the ranges of 0.1-1 µmol L^-1 and 1-30 µmol L^-1, with acceptable detection limit (30 nmol L^-1). Finally, the proposed method was used for detection of curcumin in serum samples with recoveries of 80-110.87%. The results demonstrated that aforementioned method can be used for detection of curcumin in biological samples.

Keywords: Carbon nanotubes; Curcumin; Graphene oxide; L-cysteine; Molecularly imprinted polymer; Transition metal oxide.