A biopolymer based electrolyte system has been developed using NaI as dopant salt and Arrowroot starch as polymer matrix. Problem of fungal growth in such system has been removed by the addition of Glutaraldehyde (GA). The conductivity of the Arrowroot + NaI electrolyte system is of the order of 6.7 x 10(4) S cm(1). Starch without crosslinker GA seems to be highly unstable and prone to fungal growth whereas the GA crosslinked electrolyte is quite stable. Color of the material as well as its conductivity data indicate that presence of GA affects the salt dissociation and multiplets formation. Ionic transference number of system is >= 0.95 indicating that prepared system is ionic conductor/electrolyte. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 1-7, 2011