Ionic Liquid-Carbon Nanotube Modified Screen-Printed Electrodes and Their Potential for Adsorptive Stripping Voltammetry

Compared with paraffin oil, the use of ionic liquids as a binder in carbon paste type electrodes was shown to greatly enhance the accumulation of analytes, as illustrated with 17 alpha-ethynylestradiol as a model. The ionic liquid n-octyl-pyridinium hexafluorophosphate [C(8)py][PF6] was most efficient among several ionic liquids investigated. Such preconcentration allowed a [C(8)py][PF6]-multiwalled carbon nanotubes (MWCNTs) (95:5 w/w) composite electrode to be useful for adsorptive stripping voltammetry. Screen-printed electrodes modified with [C(8)py][PF6]-MWCNTs were developed and were able to achieve high sensitivity during adsorptive stripping voltammetric measurements under optimised conditions.