Stripping voltammetric analysis of organophosphate pesticides using Ni/Al layered double hydroxides as solid-phase extraction

A sensitive electrochemical stripping voltammetric biosensor is designed for organophosphate pesticides (OPs) based on solid-phase extraction (SPE) using Ni/Al layered double hydroxides (LDHs) modified glassy carbon electrode (labeled as Ni/Al-LDHs/GCE). The Ni/Al-LDHs as the host are highly efficient to capture Cos, which dramatically facilitates the enrichment of nitroaromatic OPs onto their surface and realizes the stripping voltammetric detection of OPs. The stripping voltammetric performances of methyl parathion (MP) intercalated into LDHs were evaluated by cyclic voltammetric and square-wave voltammetric (SWV) analysis. The combination of the host-guest supramolecular structure, SPE, and stripping voltammetry provides a fast, simple, and sensitive electrochemical method for detecting nitroaromatic OPs by using MP as a model. The stripping analysis is linear over the MP concentration ranges of 0.001-0.1 and 0.2-1.0 mu g mL(-1) with a detection limit of 0.6 ng mL(-1) (S/N = 3). The developed biosensor exhibits good reproducibility and acceptable stability. This study offers a new promising protocol for OPs analysis. (C) 2009 Elsevier B.V. All rights reserved.