Novel immobilized metal ion affinity adsorbent based on cross-linked β-cyclodextrin matrix for repeated adsorption of α-amylase

β-Cyclodextrin (β-CD) was chosen as the matrix material for the affinity binding of α-amylase in this work. β-CD was cross-linked with epichlorohydrin to improve its rigidity. Iminodiacetic acid (IDA), as a ligand, was bond with the cross-linked β-CD to increase the binding affinity for α-amylase. The affinity adsorbent thus prepared was further chelated with Cu ²⁺ for the purpose of binding affinity and stability. The prepared affinity adsorbent was notated as β-CD _cl-IDA- Cu ²⁺. Excellent binding as well as de-binding was achieved within an extremely short period of time. Consequently, β-CD _cl-IDA-Cu ²⁺ successfully performed its ability on the affinity adsorption towards α-amylase. The adsorbent was also tested by its ability on repeated utilization. The result further confirmed that it could be repeatedly used and maintained the adsorption/desorption performance stably through many batches of operation. In addition, the bound α-amylase after many adsorption batches could be desorbed with a very high efficiency and hence rather high α-amylase activity could be collected.