Nonenzymatic electrochemical sensor based on imidazole-functionalized graphene oxide for progesterone detection.

The modification of electrode surfaces has been the target of study for many researchers in order to improve the analytical performance of electrochemical sensors. Herein, the use of an imidazole-functionalized graphene oxide (GO-IMZ) as an artificial enzymatic active site for voltammetric determination of progesterone (P4) is described for the first time. The morphology and electrochemical performance of electrode modified with GO-IMZ were characterized by scanning electron microscopy and cyclic voltammetry, respectively. Under optimized conditions, the proposed sensor showed a synergistic effect of the GO sheets and the imidazole groups anchored on its backbone, which promoted a significant enhancement on electrochemical reduction of P4. Figures of merits such as linear dynamic response for P4 concentration ranging from 0.22 to 14.0 μmol L-1, limit of detection of 68 nmol L-1 and limit of quantification and 210 nmol L-1 were found. In addition, presented a higher sensitivity, 426 nA L µmol-1, when compared to the unmodified electrode. Overall, the proposed device showed to be a promising platform for a simple, rapid, and direct analysis of progesterone.