Disposable screen-printed antimony film electrode modified with carbon nanotubes/ionic liquid for electrochemical stripping measurement

In this paper, two disposable screen-printed antimony film electrodes (SPSbFEs) modified with multi-walled carbon nanotubes (MWCNTs) and ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF(4)), respectively for electrochemical stripping measurement are introduced. The modified screen-printed electrode substrate was prepared by homogeneously doping the attractive material into the graphite-based printing ink, and then an antimony film was in situ formed by simultaneously electrodepositing the antimony precursor with interesting analytes on the modified substrate. The electroanalytical performance of the modified SPSbFE for heavy metals based on the anodic stripping protocol was intensively evaluated. It was found that stripping voltammetric measurements of mercury (II) and lead (II) at the modified SPSbFEs resulted in good peaks with very low background contribution. In comparison with the bare SPSbFE, the modifications of both MWCNTs and [Bmim]BF(4) were demonstrated providing more sensitive responses. The results indicated that the SPSbFE modified with 4 wt%[Bmim]BF(4) exhibited well linear behavior in the mercury (II) concentration range from 20 to 140 mu g/L (R(2) =0.998) with a detection limit of 0.36 mu g/L (S/N = 3) under a 120 s accumulation, and good repeatability with a relative standard deviation (RSD) of 4.16% (40 mu g/L, n = 12). The proposed electrodes, as new styles of mercury-free electrodes, also exhibit encouraging properties for measurements of practical samples. (C) 2011 Elsevier Ltd. All rights reserved.