Formation of Schiff's base between 2-O-(formylmethyl)-beta-cyclodextrin and chitosan with an average molecular weight of 40 000 in acetate buffer at pH 4.4, followed by reduction with sodium cyanoborohydride produced a beta-cyclodextrin-linked chitosan in a one-pot reaction. The product, which had a degree of substitution of 37%, was soluble in water at neutral and alkaline conditions. UV-visible and circular dichroism spectroscopic examinations revealed that the product had the ability to form a host-guest complex with p-nitrophenolate. (C) 1998 Elsevier Science Ltd. All rights reserved.