Organic/inorganic hybridized alginate beads were newly synthesized via sol-gel chemistry. Interaction between the azopyridine and metal ion is the main cause of Co ion detection. The beads showed improved stability and least leakage of azopyridine during use. Removal of Co ion was assessed by the ion-exchange of carboxylate groups in alginate. The beads with dual functions of detection and removal of Co ion were successfully accomplished.