A new and complex modification technique of glassy carbon electrode ( GCE) with multi-walled carbon nanotubes (MWNTs) was developed. Firstly, MWNTs were electro-deposited on GCE at 1.70 V for 2 h. Secondly, by layer-by-layer (LBL) self-assembly technique, a functional membrane of{PDDA/MWNTs}(n) were fabricated by alternative immersion in 1% PDDA solution and 1 mg L (1) MWNTs dispersion either. As a result, the modified membrane with five {PDDA/MWNTs} bilayers have good sensitivity, stability, anti-fouling ability and catalytic activity for thiocholine (TCh) detection, the oxidation potential on the modified GCE was decreased almost by 50% while the peak current was increased almost by 100% compared with that on bare GCE. Meanwhile, it showed a low detection limit of less than 7.500 x 10 (7) mol L (1) TCh. (C) 2008 Elsevier B.V. All rights reserved.