Electrochemical sensor for the determination of brucine in human serum based on molecularly imprinted poly-o-phenylenediamine/SWNTs composite film

A sensitive and selective sensor was successfully developed by integrating electropolymerization of molecularly imprinted polymer (MIP) with single-wall carbon nanotubes (SWNTs) for the determination of brucine in human serum. The imprinted poly-o-phenylenediamine (PoPD), which was embedded in SWNTs surface, functioned as a selective recognition element for brucine determination. The introduction of SWNTs into the polymer composite could enhance the electrical response by facilitating charge–transfer processes of brucine which was imprinted or rebinded in the PoPD film. The imprinted sensor was characterized via atomic force microscope (AFM) and cyclic voltammetry (CV). Under the optimal experimental conditions, the current response of the imprinted sensor was linear to the concentration of brucine in the range of 6.2 × 10−7–1.2 × 10−5 M, and a detection limit of 2.1 × 10−7 M was obtained. The imprinted sensor showed high recognition ability and affinity for brucine in comparison with non-imprinted polymer (NIP), and it was successfully applied to the determination of brucine in human serum samples with recoveries of 99.5–103.2%.