Developing a novel sensor based on ionic liquid molecularly imprinted polymer/gold nanoparticles/graphene oxide for the selective determination of an anti-cancer drug imiquimod.

Despite its useful properties, imiquimod (IMQ), known as an anti-cancer drug, can be harmful to the skin at high concentrations. Therefore, we have developed a novel electrochemical sensor to determine IMQ, for the first time. A glassy carbon electrode (GCE) was modified by a new composite comprising of ionic liquid-based molecularly imprinted polymer (MIP) and gold nanoparticles/graphene oxide (Au/GO). The MIP/Au/GO nanocomposite was synthesized through non-covalent imprinting process in the presence of IMQ, as template molecule and characterized by SEM and FT-IR. The square wave voltammetry technique (SWV) was applied for IMQ determination in 0.1 M phosphate buffer solution (PBS) at pH 7.0. Several parameters affecting the IMQ quantification were evaluated and optimized. Under the optimized conditions, the sensor presented a linear range of 0.02-20.0 µM, a limit of quantification and detection of 0.02 µM and 0.006 µM, respectively. Low RSD values indicate the good repeatability and reproducibility of the modified electrodes in preparation and determination procedures. The satisfactory results indicated that the proposed sensor could be successfully applied for IMQ determination in real samples.