Enhanced host–guest electrochemical recognition of dopamine using cyclodextrin in the presence of carbon nanotubes

A novel application of multiwall carbon nanotubes (MWCNT) for biosensor use is presented. β-Cyclodextrin (β-CD) as molecular receptor and MWCNT as enhancer of electron transfer are integrated in a dopamine (DA) electrochemical sensor system. The proposed molecular host–guest recognition based sensor has a high electrochemical sensitivity for the determination of DA. The electrochemical behaviour of DA is investigated by cyclic voltammetry (CV). The response mechanism of the MWCNT/β-CD modified electrode for DA is based on the combination of electrostatic and inclusion interaction of β-CD with DA which is distinguished from the response mechanism of non-modified electrode. The proposed integrated sensor showed improved analytical performance characteristics in catalytic oxidation of DA compared with non-modified electrode: excellent sensitivity, repeatability, stability, selectivity and recovery for the determination of DA. Under optimized conditions linear calibration plots were obtained for amperometric detection of DA over the range 0.01–0.08 mM.