Layer-by-Layer self-assembled acetylcholinesterase/PAMAM-Au on CNTs modified electrode for sensing pesticides

In this paper. an acetylcholinesterase (AChE)/dendrimers polyamidoamine (PAMAM)-Au/Carbon nanotubes (CNTs) multilayer modified electrode based on LbL self-assembled technique was employed in the detection of carbofuran in samples. The configuration of the nanostructure on the electrode provided a favorable environment to the immobilization of AChE. The modified films also improved the electrocatalytic characteristics and electron transfer speed between the films and the surface of electrode. The PAMAM-Au nanoparticles were characterized by SEM and UV-VIS methods. A set of experimental conditions were also optimized for the detection of the pesticides. A linear response over carbofuran concentration in the range of 4.8 x 10(-9) M to 0.9 x 10(-7) M was exhibited with a detection limit of 4.0 x 10(-9) M. The biosensor showed high sensitivity, good stability and reproducibility with promising application. (c) 2009 Elsevier B.V. All rights reserved.