Langmuir-Blodgett film of p-tert-butylthiacalix[4]arene modified glassy carbon electrode as voltammetric sensor for the determination of Hg(II)

The pi-A isotherms and UV-vis spectra of the transferred films suggested that the monolayer of p-tert-butylthiacalix[4]arene can coordinate with Hg2+ at the air-water surface. From these observations, a glassy carbon electrode coated with Langmuir-Blodgett film of p-tet-butylthiacalix[4]arene as a new voltammetric sensor is designed for the determination of trace amounts of Hg2+. Compared with bare glassy carbon electrode and modified glassy carbon electrode using direct coating method, the Langmuir-Blodgett film-modified electrode can greatly improve the measuring sensitivity of Hg2+. Under the selected conditions, the Langmuir-Blodgett film-modified electrode in 0.1 mol L-1 H2SO4 + 0.01 mol L-1 KCl solution shows a linear voltammetric response for Hg2+ in the range of 5.0 x 10(-10) to 1.5 x 10(-7) mol L-1, with a detection limit of 2.0 x 10(-10) mol L-1. The proposed method was also applied to determine Hg2+ in water samples (tap, lake and river water). In addition, the fabricated electrode exhibited a distinct advantage of simple preparation, non-toxicity, good reproducibility and good stability. (C) 2009 Elsevier B.V. All rights reserved.