title: Enhanced host-guest electrochemical recognition of herbicide MCPA using a β-cyclodextrin carbon nanotube sensor.
abstract: An electrochemical sensor for the determination of the chlorophenoxy herbicide MCPA has been developed, based on a combination of multi-walled carbon nanotubes with incorporated β-cyclodextrin and a polyaniline film modified glassy carbon electrode. The proposed molecular host-guest recognition based sensor has a high electrochemical sensitivity for the determination of MCPA. The electrochemical behaviour of MCPA at the chemically modified electrode was investigated in detail by cyclic voltammetry. The results indicate that the β-CD/MWCNT modified glassy carbon electrode exhibits efficient electrocatalytic oxidation of MCPA with high sensitivity, stability and lifetime. The analytical characteristics of this film were used for the quantitative determination of MCPA in natural waters. Cyclic voltammetry in phosphate buffer solution at pH 6.0, allowed the development of a method to determine MCPA, without any previous steps of extraction, clean-up, or derivatization, in the range of 10-100 μmol L(-1), with a detection limit of 0.99 μmol L(-1) in water. The results were statistically compared with those obtained through an established high-performance liquid chromatography technique, no significant differences having been found between the two methods.
authors.affiliation: Departamento de Engenharia Química, Instituto Superior de Engenharia do Porto, IPP, 4200-072 Porto, Portugal.
authors.forename: V
authors.initials: V
authors.lastname: Rahemi
authors.forename: J J
authors.initials: JJ
authors.lastname: Vandamme
authors.forename: J M P J
authors.initials: JM
authors.lastname: Garrido
authors.forename: F
authors.initials: F
authors.lastname: Borges
authors.forename: C M A
authors.initials: CM
authors.lastname: Brett
authors.forename: E M P J
authors.initials: EM
authors.lastname: Garrido
mesh_terms: D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000032:analysis* / Q000737:chemistry; D053000:Analytic Sample Preparation Methods; D000814:Aniline Compounds / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004579:Electron Transport; D006540:Herbicides / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D037742:Nanotubes, Carbon / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D006540:Herbicides; D037742:Nanotubes, Carbon; D047392:beta-Cyclodextrins; C416807:polyaniline; D014867:Water; D008456:2-Methyl-4-chlorophenoxyacetic Acid