Improved catalytic performance of porcine pancreas lipase immobilized onto nanoporous gold via covalent coupling

Abstract

Nanoporous gold (NPG) is a promising candidate material for lipase immobilization. However, the immobilization approach greatly influences the usability of immobilized lipase composites. In the present study, a type of lipase–NPG biocomposites is constructed by the covalent coupling method. The effects of immobilizing method as well as the NPG pore size on the lipase loading, catalytic activity, and stability of lipase–NPG biocomposites are investigated. The results show that the lipase–NPG biocomposite with a pore size of 25 nm obtained by using covalent coupling is an optimal strategy due to its excellent catalytic properties and remarkable stability. This particular lipase–NPG biocomposite not only retains over 85 % of its initial catalytic activity after 10 recycles but also exhibits good resistance to denaturation over a broader range of pH values and temperatures. Therefore, good activity and stability render this strategy promising in the biocatalyst field.