Graphene/graphite paste electrode incorporated with molecularly imprinted polymer nanoparticles as a novel sensor for differential pulse voltammetry determination of fluoxetine

Molecularly imprinted polymer (MIP) nanoparticles including highly selective recognition sites for fluoxetine were synthesized, utilizing precipitation polymerization. Methacrylic acid and vinyl benzene were used as functional monomers. Ethylene glycol dimethacrylate was used as cross-linker agent. The obtained polymeric nanoparticles were incorporated with carbon paste electrode (CPE) in order to construct a fluoxetine selective sensor. The response of the MIP-CP electrode to fluoxetine was remarkably higher than the electrode, modified with the non-imprinted polymer, indicating the excellent efficiency of the MIP sites for target molecule recognition. It was found that the addition of a little amount of graphene, synthesized via modified hummer's method, to the MIP-CP resulted in considerable enhancement in the sensitivity of the electrode to fluoxetine. Also, the style of electrode components mixing, before carbon paste preparation, was demonstrated to be influential factor in the electrode response. Some parameters, affecting sensor response, were optimized and then a calibration curve was plotted. A dynamic linear range of 6×10−9-1.0×10−7 mol L−1 was obtained. The detection limit of the sensor was calculated equal to 2.8×10−9 mol L−1 (3Sb/m). This sensor was used successfully for fluoxetine determination in the spiked plasma samples as well as fluoxetine capsules.