Organic-inorganic composite films have been fabricated from polyoxometalate (NH4)(5)H4PV6Mo6O40 center dot 6H(2)O (PV6Mo6) and Methyl Violet (MV) by the electrostatic layer-by-layer self-assembly method. The multilayer films have been characterized by ultraviolet-visible spectroscopy and atomic force microscopy. The obtained films of (PV6Mo6/MV)(n) show not only an electrocatalytic activity towards the reduction of NO2-, ClO3- and BrO3-, but also obviously an inhibiting effect on the growth of Escherichia coli. (C) 2014 Elsevier B.V. All rights reserved.