In this study, a novel technique combining surface imprinting and polymer crosslinking was applied to synthesize the Ag+-imprinted thiourea/glutaraldehyde grafted O-carboxymethyl chitosan (ITG-OCMC) beads which demonstrate extremely good selective adsorption of Ag+ from a bimetallic aqueous solution. Results indicated that high degree of carboxymethylation and low level of crosslinking would help to achieve higher uptake capacity of Ag+. The maximum uptake of Ag+ was found to be 156.32 mg g(-1) at 40 degrees C with an initial Ag+ concentration of 160.5 mg L-1 and the biosorbent dosage of 1.0 g L-1. Langmuir isotherm and Lagergren's pseudo-second-order kinetic can be used to describe the sorption process of Ag+. Analyses from FT-IR and XPS confirmed that selective adsorption of Ag+ took place on the surfaces of ITG-OCMC beads by chelation through >C=S, amine, carboxyl and hydroxyl groups. (C) 2014 Elsevier B.V. All rights reserved.